Outboard Repair Manual E-Book_275110 BRIGGS & STRATTON

5 HP OutboardTroubleshooting & Repair Manual

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2751

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This guide has been written and published by Briggs & Stratton Corporation to aid our dealers' mechanics andcompany service personnel when servicing the products described herein.

It is assumed that these personnel are familiar with the servicing procedures for these products, or like or similarproducts, manufactured by Briggs & Stratton Corporation. It is also assumed that they have been trained in therecommended servicing procedures for these products, which includes the use of mechanics hand tools and anyspecial tools that might be required.

Proper service and repair is important to the safe, economical and reliable operation of all engine driven systems.The troubleshooting, testing, service and repair procedures described in this guide are effective methods ofperforming such operations.

We could not possibly know of and advise the service trade of all conceivable procedures or methods by which aservice might be performed, nor of any possible hazards and/or results of each procedure or method. We havenot undertaken any such wide evaluation. Therefore, anyone who uses a procedure or method not described bythe manufacturer must first satisfy himself that neither his safety, nor the safety of the product, will beendangered by the service or operating procedure selected.

All information, illustrations, and specifications contained in this guide are based on the latest productioninformation available at the time of publication. However, Briggs & Stratton Corporation reserves the right tochange, alter, or otherwise improve the product at any time without prior notice.

Some components or assemblies of the product described in this guide may not be considered repairable.Disassembly, repair and reassembly of such components may not be included in this guide.

Copyright © 2003 Briggs & Stratton Corporation

All rights reserved.

No part of this material may be reproduced or transmitted, in any form or by any means, electronic ormechanical, including photocopying, recording or by any information storage and retrieval system, without priorpermission in writing from Briggs & Stratton Corporation.

1

TABLE OF CONTENTS

Table of Contents

5 HP Outboard • Troubleshooting & Repair Manual

INTRODUCTION1

TROUBLESHOOTING2

DISASSEMBLY3In the Interest of Safety 5

Safety Alert Symbols 5

Fuel Recommendations 6

Gasoline 6

Oil Recommendations 6

Lubrication System 6

Engine Oil 6

Oil Drain Plug, Oil Fill and Dipstick 6

Gear Selector 7

Operation 7

Reverse 8

Neutral 8

Forward 8

Changing Gear Case Oil 9

Check Lower Unit 13

No Start - Hard Start 13

Vibration 13

Power Loss 13

Noise 13

Cooling 13

Check Ignition 14

Armature Test 15

Tests for No Spark 15

Neutral Switch Test 16

Check Compression 17

Cylinder Leak Down Test 17

Check Carburetion 18

Steering Tension 18

Propeller Service 19

Cooling Shroud 23

Removal 23

Power Head 23

Blower Housing 24

Magnetron™ Ignition 24

Flywheel 25

Inspect Flywheel Key, Keyway, Flywheel and Crankshaft 26

Carburetor 26

Disassemble Carburetor 27

Carburetor Cleaning 27

Cylinder Head 28

Prepare Cylinder Head for Removal 28

Remove Valve Cover 28

Disassemble Cylinder Head 28

Crankshaft & Camshaft 29

Oil Slinger Lubrication 29

Piston and Connecting Rod 30

Gear Case Disassembly 30

Sliding Clutch 32

Midsection 33

Disassembly 33

Throttle Cable 34

Replacement 34

Rewind Starter 34

Remove Rope 34

Inspect Rope 34

Remove Pulley and Spring 34

Inspect Spring, Starter Housing and Pulley 35

2

TABLE OF CONTENTS

Table of Contents


OVERHAUL4Magnetron Ignition 39

Remove Armature 39

Inspect Valve Springs 39

Inspect Valve Guides 39

Finish Ream Valve Guides 39

Reface Valves and Seats 39

Remove Piston Rings 39

Check Piston Ring Groove Wear 40

Check Piston Ring End Gap 40

Check Connecting Rod 40

Undersized Connecting Rods 40

Check Piston Pin and Piston Pin Bore 41

Inspect Crankshaft 41

Inspect Camshaft 42

Check Cylinder 42

Cylinder Resizing 42

Set Up For Honing 42

Hone Cylinder 43

Cylinder Finish (“Cross Hatch”) 43

Cylinder Cleaning 44

Check Camshaft Bearings 44

Check Crankshaft Bearings 44

Remove DU™ Magneto Bearing 44

Install DU™ Magneto Bearing 45

Oil Seals 45

ASSEMBLY5Piston and Connecting Rod 49

Piston Rings 49

Compress Piston Rings 49

Crankshaft Installation 50

Install Connecting Rod & Piston 50

Install Camshaft 51

Install Sump 51

Crankshaft End Play 51

Install Flywheel 52

Install Armature 52

Armature Air Gap 52

Cylinder Head Assembly 53

Install Cylinder Head Plate and Rocker Arm Studs 53

Install Valves 53

Install Valve Springs and Retainers 53

Install Cylinder Head 54

Install Rocker Arms 54

Adjust Valve Clearance 55

Install Valve Cover 55

Carburetor Assembly 55

Install Welch Plug 55

Install Choke Shaft 56

Install Throttle Shaft 56

Install Inlet Needle and Float 56

Install Carburetor 57

Install Pulley and Spring 57

Install Pawls, Pawl Springs & Retainer 58

Wind Spring & Install Rope 58

Install Blower Housing 59

Gear Case Assembly 59

Mid Section Assembly 62

Install Power Head 63

Cooling Shroud Installation 64

Adjust Throttle Cable 64

Idle Adjustment 65

APPENDIX6Outboard Engine Fastener Specifications 68

Lower Unit Fastener Specifications 68

Ignition System Wiring Diagram 69

Component Location - Gear Case 70

Component Location-Midsection 72

1

3

Section 1 • Introduction


IntroductionIn the Interest of Safety 5

Safety Alert Symbols 5

Fuel Recommendations 6

Gasoline 6

Oil Recommendations 6

Lubrication System 6

Engine Oil 6

Oil Drain Plug, Oil Fill and Dipstick 6

Gear Selector 7

Operation 7

Reverse 8

Neutral 8

Forward 8

Changing Gear Case Oil 9

4



1

WARNING

The engine exhaust from this product containschemicals known to the State of California to causecancer, birth defects, or other reproductive harm.

WARNING

ADDING FUEL• Fill fuel tank outdoors or in well ventilated area.

• Do not fill portable fuel tank while it is in the boator inside a vehicle. Always place tank on theground when filling with gasoline.

• Do not overfill tank. Fill tank to approximately 1-1/2 inches below top of neck to allow for fuelexpansion.

• Keep all fuel away from sparks, open flames, pilotlights, heat, and other ignition sources.

• Do not smoke when refueling.

• Check fuel lines, tank, cap and fittings frequentlyfor cracks or leaks. Replace if necessary.

• Locate the fuel tank in a position that keeps thevent higher than the fuel level.

STARTING ENGINE• Make sure spark plug, muffler and fuel cap are in

place.

• Line from fuel tank is correctly connected to theengine.

• Do not crank engine with spark pklug removed.

• If fuel spills, wait until it evaporates before startingengine.

• If engine floods, set choke to RUN position(choke open), place throttle in FAST position andcrank until engine starts.

TRANSPORTING EQUIPMENT• Transport outboard with transport valve in the

OFF position.

STORING EQUIPMENT• Store away from furnaces, stoves, water heaters,

clothes dryer or other appliances that have pilotlight or other ignition source because they canignite fuel vapors.

Fuel and its vapors are extremelyflammable and explosive.Fire or explosion can causesevere burns or death.

DANGER

WARNING

• Do not allow any open flame, spark, heat, or litcigarette around battery during, and for severalminutes after charging.

• Wear protective goggles, rubber apron, andrubber gloves.

Storage batteries give offexplosive hydrogen gas duringrecharging.

Hydrogen gas stays aroundbattery for a long time afterbattery has been charged.

Slightest spark will ignitehydrogen and cause explosion.

You can be blinded or severelyinjured.

Battery electrolyte fluid containsacid and is extremely caustic.

Contact with battery fluid willcause severe chemical burns.

WARNING

• Be sur e the shift selector is in NEUTRALposition before attempting to start the outboard.

• When starting engine, pull cord slowly untilresistance is felt, then pull rapidly.

• Allow the cord to retract slowly.

Rapid retraction of starter cord(kickback) will pull hand and armtoward engine faster than youcan let go.

Broken bones, fractures, bruisesor sprains could result.

WARNING

• If there is a natural or LP gas leak in the area, donot sart engine.

• Do not use pressurized starting fluids becausevapors are flammable.

Starting engine creates sparking.Sparking can ignite nearbyflammable gasses.

Explosion and fire could result,causing serious injury or death.

WARNING

• Avoid contact with propeller. Keep people andpets away from propeller while the engine isrunning.

• DO NOT run the outboard out of the water.

• Operate equipment with guards in place.

• Keep hands and feet away from rotating parts.

• Tie up long hair and remove jewelry.

• Do not wear loose-fitting clothing, danglingdrawstrings or items that could become caught.

• Keep lines, rigging and other equipment inside theboat.

Rotating parts can contact orentangle hands, feet, clothing,hair or accessories.

Traumatic amputation or severelaceration can result.

WARNING

BEFORE PERFORMINGADJUSTMENTS OR REPAIRS• Disconnect spark plug wire and

keep away from spark plug.

WHEN TESTING FOR SPARK• Use approved BRIGGS & STRATTON spark plug

tester Part No. 19368.

• Do not check for spark with spark plug removed.

Unintentional sparking can resultin fire or electric shock.

Unintentional start-up can result inentanglement, traumaticamputation or laceration.

DESIGNED FOR FRESH WATER

CAUTION: Salt water is extremely corrosiveto outboard components. Failure or damage relatedto salt water corrosion is NOT covered under theBRIGGS & STRATTON Warranty.

• Do not touch hot surfaces.

• Allow equipment to cool before touching.

Running engines produce heat.Temperature of muffler andnearby areas can reach or exceed150°F (65°C).

Severe burns can occur.

HAZARD SYMBOLS AND MEANINGS

Toxic Fumes Electrocution

Hot Surface Chemical Burns

PressureUnstableMoving Parts

Fire

Explosion

5

In the Interest of SafetySafety Alert Symbols

The safety alert symbol ( ) is used to identify safetyinformation about hazards that can result in personal injury.A signal word (DANGER, WARNING, CAUTION) isused with the alert symbol to indicate the potential severityof injury. In addition, a hazard symbol may be used torepresent the type of hazard.

DANGER: Indicates a hazard which, if not avoided,will result in death or serious injury.

WARNING: Indicates a hazard which, if notavoided, could result in death or serious injury.

CAUTION: Indicates a hazard which, if notavoided, might result in death or seriousinjury.

NOTE: This notation is used to inform you of amethod, reference or procedure that could assistwith specific operations or decisions.

• DO NOT run engine in an enclosed area. (Exhaustgases contain carbon monoxide, an odorless anddeadly poison.)

• DO NOT place hands or feet near moving orrotating parts.

• DO NOT operate engine if gasoline is spilled orwhen smell of gasoline is present or otherexplosive conditions exist. (Move equipment awayfrom spill and avoid any ignition until gasoline hasevaporated.)

• DO NOT tamper with links or other parts toincrease engine speed. (This engine uses a non-adjustable, electronic engine speed limiter.)

• DO NOT run engine without the blower housingor with other safety shields removed when doingrepairs.

• DO NOT crank engine with spark plug removed.(If engine is flooded, place throttle in the FASTposition and crank until engine starts.)

• DO NOT operate engine without a muffler.(Inspect periodically and replace if worn or leaking.If engine is equipped with muffler deflector, inspectperiodically and replace if necessary. Replacementparts must be same as on original equipment.)

• DO NOT run the outboard unless the propeller iseither removed from the outboard or in water.Remove the spark plug lead and select NEUTRALwhen servicing the outboard. Remove the propellerwhenever it is necessary to test run the outboard.

• PRIOR TO WORK, read and understand thesection(s) of this manual that pertain to the job.Follow all safety warnings.

• PULL STARTER CORD SLOWLY untilresistance is felt. Then pull cord rapidly to avoidkickback and prevent hand or arm injury.

• WEAR suitable eye protection (safety glasses,goggles or face shield) when performing repairprocedures.

• PREVENT ACCIDENTAL STARTING byremoving spark plug wire from spark plug whenservicing engine or equipment.

• USE fresh gasoline. Stale fuel can gum carburetorand cause leakage.

• CHECK fuel lines and fittings frequently for cracksor leaks. Replace if necessary.

• USE Genuine Briggs & Stratton Parts or theirequivalent ONLY. The use of replacement parts,which are not of equivalent quality, may damage theengine.

INTRODUCTION



1

CAUTION: When used without the alert symbol,indicates a situation that could result in damage toequipment.

CAUTION

• Death, personal injury and/or property damagemay occur unless service instructions are followedcarefully.

• Failure to follow the warnings listed belowcould result in death, serious injury(including paralysis) or property damage.

Before attempting to service thisequipment, read the entireowner's manual and operatinginstructions.

6

Fuel RecommendationsGasoline

Use clean, fresh, unleaded gasoline. Leaded gasoline may beused if unleaded is not available. A minimum of 85 octane isrecommended. The use of unleaded gasoline results infewer combustion deposits and longer valve life.

NOTE: We do not recommend the use of gasolinethat contains alcohol, such as gasohol. However, ifused, it must not contain more than 10 percentEthanol and must be removed from the engineduring storage. Do not use gasoline that containsMethanol.

Only purchase a 30-day supply of gasoline. Fresh gasolineminimizes gum deposits and also will ensure fuel volatilitytailored for the season in which the engine will be operated.

NOTE: The use of a fuel additive, such as Briggs &Stratton Gasoline Additive (#5041) or equivalent,will minimize the formation of fuel gum depositsduring storage. Such an additive may be added to thefuel tank or storage container.

Oil RecommendationsLubrication System

Oil has four purposes. It cools, it cleans, it seals, and itlubricates. This engine is lubricated with an oil slinger.During normal operation, small particles of dust, metal fromthe cylinder walls, pistons, bearings, and combustiondeposits will gradually contaminate the oil. If the oil is notchanged regularly, these foreign particles can causeincreased friction and an abrasive action, which shortens thelife of the engine. Fresh oil also assists in cooling. Old oilgradually becomes thick and loses its cooling ability andlubricating qualities.

Engine Oil

Use a high quality detergent oil classified "For Service SF,SG, SH, SJ" or higher. Briggs & Stratton stronglyrecommends the use of synthetic oil such as Briggs &Stratton (#100030C) or equivalent. If not available, SAE 30weight oil is an acceptable substitute. No special additivesshould be used with recommended oils.

Do not mix oil with gasoline.

Air-cooled engines run hotter than automotive engines.The use of multi-viscosity oils, (10W-30 etc.) in ambienttemperatures above 40°F (4°C), will result in high oilconsumption. If multi-viscosity oil is used, check oil levelmore frequently to prevent any possible engine damagedue to lack of lubrication.

SAE 30 oil, if used in ambient temperatures below 40°F(4°C), will result in hard starting and possible enginedamage due to inadequate lubrication.

Synthetic oil meeting ILSACGF-2, API certification markand API service symbol with "SJ/CF ENERGYCONSERVING" rating or higher, is acceptable oil at alltemperatures.

NOTE: Use of synthetic oil does not alter therequired oil change intervals.

Oil Drain Plug, Oil Fill and Dipstick1. Change oil every 25 hours.

2. Position the engine vertically to check or change theoil.

3. Remove oil drain plug (Figure 1) . Drain oil whileengine is still warm.

1



1

Figure 1 — Oil Drain Plug

STARTING TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE

°C

°F -20 0 20 40 60 80 100

-30

Synthetic 5W-30W, 10W-30

SAE 30

32

-20 -10 0 10 20 30 40

1

1

7

4. Install drain plug. Torque to 10 ft. lbs. (14 Nm).

5. Remove dipstick (Figure 2) . Refill slowly with 24 oz. (0.75 qt., 0.7 L) of new oil with the properservice classification and viscosity grade. Do notoverfill.

6. Install the dipstick.

7. Start and run engine at idle to check for oil leaks.

8. Check the oil level. The oil level should be betweenthe ADD and FULL marks on the dipstick. Add newoil if required (Figure 3).

Gear SelectorOperation

The outboard operator selects gears with the shift lever

handle (Figure 4) on the starboard (right) side of the

outboard which acts on the shift cam/rod assembly . Theshift lever is connected to the shift cam/rod by an upper

rod . The rods are connected with a clamp that alsoprovides for NEUTRAL adjustment.

The forward gear (Figure 5) and reverse gear are

driven simultaneously by the pinion gear and spin freely

on the propeller shaft . The spring inside the

propeller shaft applies forward pressure on the roll pin ,

sliding clutch and shift cam follower . The shift

cam/rod is stepped to control the location of the slidingclutch through the shifter pin. The sliding clutch is splinedto the propeller shaft.

4

109

8

75

11

612

32

4

1

2



Figure 4 — Gear Selector Operation

Figure 5 — Forward Gear

Figure 2 — Dipstick

Figure 3 — Dipstick Markings

2

3

4

1

2

3

4

11

5

7

8

9

6

12

10

8

Reverse

When the shifter is moved to the REVERSE position, the

shift cam (Figure 6) is pressed down to its lowestposition in the gear case. The highest surface of the cam

presses the cam follower rearward, engaging the sliding

clutch to the REVERSE gear .

Neutral

When the shifter is in the NEUTRAL position the shift cam

(Figure 7) is in the middle position. The cam-follower

is on the middle detent of the shifter cam. The sliding

clutch is not engaged to either the FORWARD or theREVERSE gears.

Forward

When the shifter is set to the FORWARD position, the

shift cam (Figure 8) is pulled to its highest position in

the gear case. The spring inside the propeller shaft

pushes the sliding clutch and cam follower forward,

engaging the sliding clutch to the FORWARD gear .8

65

3

9

5

6

9

25

6

9



1Figure 6 — Reverse

Figure 7 — Neutral

Figure 8 — Forward

2

9

9

9

3 5

5

5

6

6

6

8

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Changing Gear Case Oil1. Remove oil drain/fill plug (Figure 9) and vent plug

.

2. Drain the gear lube into an approved container.

3. Fill gear case with 4 oz. of 80-90Wgear oil.

Insert the tip of the oil bottle into the oil fill (lower) hole.Squeeze the bottle until the oil is just to the point ofoverflowing at the vent (upper) hole.

4. Install vent plug in top hole. Torque to: 20 in. lbs. (2 Nm).

5. Install oil drain/fill plug in lower hole. Torque to: 45 in. lbs. (5 Nm).

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Figure 9 — Gear Case Oil

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11

Section 2 • Troubleshooting


2Troubleshooting 13

Check Lower Unit 13

No Start - Hard Start 13

Vibration 13

Power Loss 13

Noise 13

Cooling 13

Check Ignition 14

Armature Test 15

Tests for No Spark 15

Neutral Switch Test 16

Check Compression 17

Cylinder Leak Down Test 17

Check Carburetion 18

Steering Tension 18

Propeller Service 19

Troubleshooting

12



2

13

TroubleshootingMost complaints concerning engine operation can beclassified as one or a combination of the following:

No Start

Hard Start

Lack of Power

Vibration

Overheating

High Oil Consumption

When the cause of a malfunction is not readily apparent,perform a check of the compression, ignition,carburetion and cooling systems. This check-up,performed in a systematic manner, can usually be done in amatter of minutes. It is the quickest and surest method ofdetermining the cause of failure. This check-up will pointout potential future failures, which can be corrected inadvance. The basic check-up procedure is the same for allengine models.

Check Lower Unit

What appears to be a problem with engine operation, suchas hard starting, vibration, etc., may be the fault of thelower unit rather than the engine itself. Listed are the mostcommon effects of problems and probable causes.

No Start - Hard Start

1. Check remote control assembly for properadjustment.

2. Check neutral safety system for shorted wires, looseor corroded connections, or defective modules orswitches.

Vibration

1. Mounting bolts loose - tighten.

2. Check for lower unit damage.

Power Loss

1. Bind or drag in unit - place engine in NEUTRAL.

Operate lower unit manually to check for binding.

2. No lubrication in lower unit.

Noise

1. No lubricant in lower unit.

2. Worn bearings or gears.

CoolingChaff or dirt can clog the cooling system, especially afterprolonged service in very dusty conditions. Continuedoperation with a clogged cooling system can cause severeoverheating and possible engine damage. Periodically inspect

the cylinder fins (Figure 10) and fan . Clean asrequired. Clean and inspect more often when dust or when

airborne debris is present.

21

TROUBLESHOOTING



2

Figure 10 — Cooling Fins

2

1

WARNING

To prevent accidental starting, thespark plug wire must be removedfrom the spark plug and groundedafter removing boot. Failure to do socan cause personal injury. If thepropeller or propeller shaft is turnedwith the outboard in gear it ispossible that the engine will crankover and start. Remove the spark pluglead and select NEUTRAL whenservicing the outboard. To preventserious injury from contact with arotating propeller, do not run theoutboard unless the propeller iseither removed from the outboard orthe unit is in water. Remove thepropeller whenever it is necessary totest run the outboard..

14

1. Safety/Engine Stop Switch

2. BLACK Wire

- to Safety/Engine Stop Switch

3. Connector

4. BLACK Wire

- Armature Ground

5. Armature

6. Spark Plug

7. BLACK Wire

- to Speed Limiter

8. Not Used

9. Neutral Switch

10. FORWARD Position

11. NEUTRAL Position

12. REVERSE Position

13. BLACK Wire

14. Wiring Harness Connector

to Engine Speed Limiter

15. WHITE Wire

16. Engine Ground

17. RED Wire

Check Ignition

Attach Tester (#19368) to the spark plug wire and groundthe tester to the engine block. Spin the flywheel with theengine starter. If spark jumps the tester gap, the ignitionsystem is performing satisfactorily. If spark does not occur,look for;

• Incorrect ignition armature air gap

• Shorted stop switch wire

• Shorted safety/engine stop switch

• Ignition armature failure

• Defective Speed Limiter

NOTE: If engine runs but misses during operation,a quick check to determine if ignition is faulty can bemade by inserting the spark plug tester between theignition cable and the spark plug. A spark miss will benoticeable in the window of the tester.



2

Figure 11 — Ignition Schematic

21

11

12

131617

15 14

10

9

3 4

5

6

7

8

WARNING

Be sure there is no fuel or fuelvapor present, which might beignited by the spark and cause afire or explosion. Do not removespark plug for this test..

15

Armature Test

1. Disconnect the ground lead (Figure 12) to thearmature,

2. Connect spark plug wire to long terminal of Spark

Tester (#19368) and ground tester to engine.

3. Pull the starter rope and observe the spark gap in thetester. If the spark jumps the tester gap, the armatureis good.

4. If there is no spark, check the ground lead forpinching, worn insulation or damage. Test the lead forcontinuity. If the ground lead is undamaged and hascontinuity, replace the armature.

Tests for No Spark

NOTE: Perform these tests if the armature is goodand there is still no spark.

1. Remove the cowl from the power head.

2. Disconnect the armature ground lead.

3. Remove safety/engine stop switch clip (Figure 13) .

4. Disconnect the wiring harness connector (Figure 14)

from the engine speed limiter.

5. Insert the test probe to the wire harness side of the

armature ground wire connector ,

6. Test the switch for continuity at the engine ground

.

There should be continuity.

2

4

3

1

2

1

3



2Figure 12 — Armature Test

Figure 13 — Safety Stop Switch Clip

Figure 14 — Disconnect Speed Limiter

1

1

2

3

2

3

4

WARNING

Do not remove spark plug whenchecking ignition. A fire orexplosion may occur. Always usean approved spark tester.

16

7. Insert clip to safety/engine stop switch (Figure 13)and retest the switch for continuity.

There should be no continuity.

Use steps 6 and 7 to verify a working safety/engine stopswitch and wires.

NOTE: Leave the test probe connected to thearmature ground wire connector (step 5) for thefollowing steps.

8. Test the black wire (Figure 15) for continuity at

the connector to the engine speed limiter.

There should be continuity.

9. Test the white wire for continuity at theconnector to the engine speed limiter. There shouldbe no continuity.

10. Depress the safety/engine stop switch. There shouldbe continuity only when the switch is depressed.

If there is still no spark replace the engine speed limiter.

Neutral Switch Test1. Disconnect the wiring harness connector (Figure 16)

from the engine speed limiter.

2. Place the shift lever to NEUTRAL. Test for continuity

between the wiring harness connector and theengine ground.

3. Repeat the test with the shift lever in the FORWARDand REVERSE positions.

There should be continuity with the shift lever NEUTRAL,and no continuity in the FORWARD and REVERSEpositions.

4. Remove the power head (See Section 3).

5. Make sure the wire to the switch was not pinched ordamaged.

6. Make sure the actuating pin of the shift lever actuatesthe switch in the NEUTRAL position, and does notactuate the switch when shifted to FORWARD orREVERSE.

7. Check for continuity from the actuating pin on the

shift lever (Figure 17) to the wire harnessconnector. There should be continuity with the shiftlever in NEUTRAL only.

9

8

5

7

5

6

1



2

Figure 16 — Neutral Switch Test

Figure 15 — Continuity Test 5

8

5

7

6

17

NOTE: Local laws may require the use of aresistor spark plug to suppress ignition signals. If anengine was originally equipped with a resistor sparkplug, be sure to use a resistor spark plug forreplacement.

Check CompressionIf compression is poor, look for:

Loose Spark Plug

Loose cylinder head bolts

Blown cylinder head gasket

Burned valves or valve seats

Insufficient valve clearance

Warped or worn valve stems and guides

Worn bore and/or piston rings

Broken connecting rod

Cylinder Leak Down Test

1. Run engine for 5 minutes, allowing engine to reachoperating temperature.

NOTE: If the engine is cold or cannot be started,airflow may be higher (gauge readings lower) becausecompression components are not at normaloperating temperatures.

2. Remove spark plug from engine. Disconnect crankcasebreather tube.

3. Rotate crankshaft in direction of operation until pistonis at top dead center (TDC) of compression stroke.

4. Hold flywheel nut with 15/16" socket and 1/2" breakerbar (Figure 18).

5. Connect tester (#19545) to a shop air source withminimum air pressure of 70 psi (480 KPA).

6. Install outlet hose into spark plug hole of cylinderbeing tested. Insure o-ring is seated to prevent air leakat spark plug hole. Connect other end to tester.

7. While securely holding the flywheel nut with thebreaker bar and socket, pull the knob lock out in thedirection of the arrow. Slowly turn the regulator

adjustment knob (Figure 19) clockwise untiltester's needle is on the set point. Push in regulatoradjustment knob.

1



2

Figure 18 — Holding The Flywheel

Figure 19 — Adjusting Compression Tester

Figure 17 — Shift Lever Continuity Test

9

1

CAUTION

Injury may occur if thecrankshaft is allowed torotate.The crankshaft must beheld with the piston at top deadcenter to eliminate any chance ofrotation..

18

8. Slowly open the valve and note the reading on thegauge.

9. Listen for air leaking from cylinder head gasket,carburetor, exhaust system and either crankcasebreather or high oil fill dipstick tube.

NOTE: If a high flow of air is leaking from exhaustand carburetor, make sure that piston is at TDC oncompression stroke.

• Air flowing between cylinder and cylinder headindicates that cylinder head gasket is leaking.

•. Air flowing from carburetor indicates air isleaking past intake valve and seat.

• Air flowing from exhaust system indicates air isleaking past exhaust valve and seat.

• Air flowing from crankcase breather tube or highoil fill dipstick tube indicates air is leaking pastpiston rings.

10. When test is complete, close the valve. Push theregulator lock nut IN and turn counterclockwise asfar as it will go to release pressure in combustionchamber.

11. Disconnect outlet hose from tester before removingfrom spark plug hole.

Check CarburetionBefore making a carburetion check, fill the fuel tank withfresh, clean gasoline. Be sure that the shut-off valve isOPEN. Check to see that the choke closes completely. Ifengine will not start, remove and inspect the spark plug.

If plug is wet, look for:

• Over choking

• Excessively rich fuel mixture

• Water in fuel

• Inlet needle stuck open

• Fouled spark plug

If plug is dry, look for:

• Leaking carburetor mounting gaskets

• Dirt or gum deposits in carburetor, fuel filter, fuellines, transport valve or fuel tank

• Inlet needle stuck shut

• Inoperative fuel pump

A simple check to determine if the fuel is getting to thecombustion chamber through the carburetor is to removethe spark plug and pour a small quantity of gasoline throughthe spark plug hole. Replace the plug. If the engine fires afew times and then stops, look for the same conditions asfor a dry plug.

Steering Tension1. Steering tension is adjusted with a set screw

(Figure 20) on the left side of the mid-section thatapplies pressure to a friction pad. Tighten the steering(increase steering effort) by turning the set screwclockwise; loosen (reduce steering effort) by turningthe screw counterclockwise.

1



2Reading is Green

Reading is Yellow, small leakat cylinder head gasket.

Reading is Yellow/Red, mini-mal leakage from one

component.

Reading is Red, air is leakingfrom several components.

Check that piston is at TDCon compression stroke. Ifreading does not change,

look for problems beginningwith component that

appeared to leak the mostair. Re-test after repair.

Look for a problem with thatcomponent.

Replace gasket and retest.

Good Condition

19

Propeller Service1. Remove the stainless steel lock nut (Figure 21) ,

stainless steel washer and the propeller fromthe propeller shaft.

2. Press the coupling assembly out of the propeller.

3. Inspect the coupling components (Figure 22) forwear and damage. If either the inner or outer couplingshow wear or damage, replace the coupling.

4. Inspect the exposed end of the propeller shaft for

wear or damage. If the threads (Figure 23) or hex

portion show wear or damage replace the shaft.

5. Inspect the propeller (Figure 21) for broken ordamaged blades, and for wear or damage to the hub.Replace or repair the propeller as required.

6. Install the coupling to the propeller.

7. Apply anti-seize to the propeller shaft. Install thepropeller, stainless steel washer and stainless steellock nut to the propeller shaft. Torque to 90 in. lbs. (10 Nm).

2

3

4

1

23

1



2

Figure 21 — Propeller Mounting Hardware

Figure 22 — Propeller Drive Couplings

Figure 23 — Propeller Drive Shaft

Figure 20 — Steering Tension Adjustment

1

1

1

3

2

3

4

20



2

21

Section 3 • Disassembly


3Disassembly

Disassembly 23

Cooling Shroud 23

Removal: 23

Power Head 23

Blower Housing 24

Magnetron™ Ignition 24

Flywheel 25

Inspect Flywheel Key, Keyway, Flywheel and Crankshaft 26

Carburetor 26

Disassemble Carburetor 27

Carburetor Cleaning 27

Cylinder Head 28

Prepare Cylinder Head for Removal 28

Remove Valve Cover 28

Disassemble Cylinder Head 28

Crankshaft & Camshaft 29

Oil Slinger Lubrication 29


Gear Case Disassembly 30

Sliding Clutch 32

Midsection 33

Disassembly 33

Throttle Cable 34

Replacement 34

Rewind Starter 34

Remove Rope 34

Inspect Rope 34

Remove Pulley and Spring 34

Inspect Spring, Starter Housing and Pulley 35

22



3

23

Cooling Shroud

NOTE: The cooling shroud must be removed toaccess the power head, wiring harness and otherserviceable components.

Removal

1. Remove the top cover.

2. Remove the dipstick.

3. Remove safety/engine stop switch clip and the switch

(Figure 24) .

4. Remove cowl.

NOTE: Do not lose the nylon spacers from thestandoffs.

5. Remove starter handle and insert.

NOTE: Pull starter rope out approximately 18"

and tie a temporary knot (Figure 25) in the

starter rope. Remove handle insert from handle

and pull the knot from the handle insert.Untie knot, remove insert and handle from rope.

6. Remove the starter rope from the shroud. Removethe shroud from the engine.

Power Head1. Cut wire ties holding the throttle cable to the

starboard (right) side of the rear handle.

2. Remove nuts (Figure 26) washers and bolts.

NOTE: The bolt on the starboard side of theengine is longer than the bolts on the port (left) side.Do not interchange bolts from side-to-side.

1

13

2

4

1

DISASSEMBLY



3

Figure 24 — Engine Stop Switch

Figure 25 — Temporary Knot

Figure 26 — Power Head Mount Bolts!

1

2

4

3

1

1

24

3. Remove the throttle cable clamp (Figure 27) .

4. Disconnect the throttle cable from the carburetor.

5. Disconnect the choke control rod (Figure 28)from the choke lever.

6. Disconnect the fuel line at the fuel fitting.

7. Remove two nuts , washers and bolts.

8. Lift the power head from the midsection. Disconnectthe neutral switch wires from the wiring harness.

9. Remove the power head.

Blower Housing1. Remove four screws (Figure 29A and B) , two

from front and two from rear of blower housing asshown.

Magnetron™ Ignition

NOTE: The flywheel does not need to be removedto service Magnetron™ ignition except to check thekeyway, flywheel key and oil seal. Replace anydamaged parts.

1. Remove blower housing.

2. Remove the spark plug wire from the spark plug.

3. Remove armature mounting screws (Figure 30) ,

disconnect stop wire . Lift off armature.2

1

4

7

6

5

4



3

Figure 30 — Armature Removal

Figure 27 — Throttle Cable Clamp

Figure 28 — Port Side Components

5

4

6

7

Figure 29 — Blower Housing Removal

A B

4

4

2

1

25

NOTE: Elbow (Figure 31) does not need to beremoved except to be replaced if damaged.

FlywheelRemove the blower housing and rewind assembly to accessthe flywheel.

1. Use the correct flywheel holder (Figure 32) toprevent the flywheel from turning.

2. Use socket and breaker bar to remove flywheelnut.

3. To remove flywheel, use Tool (#19203), FlywheelPuller (Figure 33).

NOTE: Positioning retainer nuts (Figure 33) onthe puller screws is necessary to prevent damage tothe flywheel.

4. Thread flywheel nut onto crankshaft until top of nut isflush with end of crankshaft threads.

5. Install the flywheel puller to the flywheel.

6. Turn puller screws into flywheel puller holes untilscrews bottom or puller contacts flywheel nut

(Figure 34) .

7. Tighten puller nuts or screws equally untilflywheel loosens.

NOTE: If the screws on Flywheel Puller Toolare too short, use two cylinder head bolts(#94622), or two cylinder head studs ( #94776),and two flat washers ( #225137) in place of originalscrews.

6

65

4

3

2

1



3

Figure 31 — Plug Elbow

Figure 32 — Holding The Flywheel

Figure 33 — Flywheel Puller (#19203)

Figure 34 — Remove Flywheel

21

3

4

5

3

6

CAUTION: Do not strike flywheel to remove.

26

Inspect Flywheel Key, Keyway,Flywheel and Crankshaft

Replace the flywheel key (Figure 35) if inspection

reveals any shearing . Flywheel should be inspected forcracks, burrs on taper or keyway, and distortion of keyway.Check taper of crankshaft for burrs, rust, or other damage.Check fan or flywheel for broken fins. Replace any damagedcomponents with new parts.

Carburetor1. Turn the fuel shutoff valve to the OFF position and

drain the carburetor

NOTE: Do not use a bolt or screw in the fuel hoseto stop fuel leakage. Screw threads will loosenrubber particles which will get into the fuel system.

2. Disconnect choke (Figure 36) and throttle linkages.

3. Remove fuel pump retaining strap .

3. Remove speed limiter retaining strap.

4. Remove screws, (Figure 37) . Set aside air hornand gasket. Disconnect breather tube.

5. Disconnect fuel line at carburetor.

6. Remove screws (Figure 38) , carburetor andcontrol bracket.

7. Disconnect throttle link from carburetor.

5

1

1

32

2

1



3

Figure 37 — Air Horn Removal

Figure 38 — Carburetor Mounting Screws

Figure 35 — Flywheel Key

Figure 36 — Remove Carburetor Components

2

1

5

1

27

Disassemble Carburetor

1. Remove bowl screw/fixed main jet (Figure 39)

with fiber washer .

2. Remove float bowl and bowl gasket from carburetor.

3. Remove float hinge pin , float and inlet needle

.

NOTE: Inlet seat is not replaceable.

4. Remove idle speed screw with spring (Figure 40) ,when used.

5. Remove the limiter cap from the mixture screw.

Remove mixture screw and spring .

6. Rotate throttle shaft to closed position. Remove

throttle plate screw .

7. Remove throttle plate and throttle shaft with foamseal.

8. Grasp choke plate and remove from choke shaft

.

9. Remove choke shaft and foam washer.

10. With a modified 5/32" pin punch , remove welch

plug from carburetor body.

Carburetor Cleaning

1. Disassemble carburetor.

2. Remove all old gaskets, seals and sealing material.

3. Use commercial carburetor cleaning solvents such asBriggs & Stratton Spray Cleaner (#100041 or#100042), to clean carburetor parts and body.

4. Do not leave non-metallic parts (plastic, nylon, minlon,etc.) in commercial carburetor cleaner bath more than15 minutes.

NOTE: Parts containing rubber, such as seals, o-rings or pump diaphragms should never be placedin commercial carburetor cleaner bath.

5. Use only compressed air (blowing in both directions)to clean out all openings and passages.

6. Do not use wires, drills or any other devices to cleanout metering holes or passages.

10

11

7

6

9

12

8

5

43

2

1



3

Figure 39 — Carburetor Float Components

Figure 40 — Remove Welch Plug

1

2

3

4

5

11

7 88

9

6

12

10

28

Cylinder HeadPrepare Cylinder Head for Removal

Before cylinder head can be removed, muffler guard andmuffler must be removed.

Remove Valve Cover

1. Remove four screws (Figure 41) from valve cover

2. Remove valve cover and gasket.

3. Remove four cylinder head bolts (Figure 42) .

4. Remove the cylinder head.

Disassemble Cylinder Head

1. Loosen rocker arm adjusting nut set screws

(Figure 43) . Remove rocker arm adjusting nuts

and rocker arms .

2. Pull the push rods from the push rod guides. Label thepush rods for correct assembly.

3. Remove cylinder head plate with rocker arm studs.

4. Remove valve caps .

5. Place cylinder head on work surface.

6. Press down on spring retainer (Figure 44) withthumbs to compress valve spring. Compress springuntil large end of slot in retainer can be lined up withend of valve stem.

6

4

3

21

2

1



3

Figure 43 — Rocker Assembly

Figure 44 — Valve Spring Retainers

Figure 41 — Valve Cover

Figure 42 — Cylinder Head Bolts

1

27

1234

6

29

7. Slowly relieve tension on spring and retainer.

8. Remove retainer, spring, valve and valve stem seal(intake only). Discard valve stem seal.

9. Repeat for exhaust valve.

NOTE: If push rod guides (Figure 44) are worn,replace before installing cylinder head plate.

Crankshaft & CamshaftBefore removing the crankshaft from the engine, removerust, paint, or burrs from the PTO end of crankshaft. Thiswill reduce the chance of damaging the oil seal, sump orsump bearing.

1. Drain oil from crankcase.

2. Remove seven screws (Figure 45) , to removecrankcase sump. If the sump sticks, tap lightly with asoft hammer on alternate sides near dowel pins.

NOTE: It is not necessary to remove dowel pins.

3. Tip engine over onto flywheel side of crankcase.

4. Support engine to prevent end of crankshaft fromresting on workbench.

5. Rotate crankshaft until timing mark on crankshaft

(Figure 46) aligns with timing mark on camshaft

.

6. With camshaft in this position, the valve tappets willremain clear of cam lobes. Lift out camshaft.

7. Remove tappets.

Oil Slinger LubricationThe oil slinger (Figure 47) is driven by the cam-gear .The oil slinger lubricates the valve tappets, connecting rod,cylinder, piston and rings.

1. Remove the sump to access the oil slinger.

2. Inspect the slinger gear teeth for wear, broken teeth,broken slinger paddles, or burrs on teeth. Replace ifworn or damaged.

21

3

2

1

7



3Figure 45 — Remove Sump Cover

Figure 46 — Engine Timing Marks

Figure 47 — Oil Slinger Assembly

1

2

3

1

2

30

Piston and Connecting Rod1. Remove any carbon or ridge at top of cylinder bore

to prevent ring breakage.

2. Remove connecting rod cap bolts (Figure 48) andcap.

3. Push piston and rod out through top of cylinder.

4. Remove crankshaft.

Gear Case Disassembly1. Drain the gear case.

2. Remove the stainless steel lock nut (Figure 49) ,

stainless steel washer and propeller from the

propeller shaft .

3. Use Briggs & Stratton Socket (#19557), to loosen thepropeller shaft carrier (Figure 50).

NOTE: Always loosen the shaft carrier with thegear case attached to the midsection. The shaftcarrier is LEFT-HANDTHREAD.

4. Remove the drive shaft housing plug. Loosen (do not

remove) the shift rod clamp set screw (Figure 51) .

5. Remove the nut (Figure 52) and screw .Remove the gear case from the midsection.

67

6

4

12

3

1



3

Figure 51 — Drive Shaft Housing Plug

Figure 49 — Propeller Assembly

Figure 50 — Removing Propeller Shaft Carrier

Figure 48 — Connecting Rod Cap Bolts

6

1

1

2

3

4

Tool (#19557)

31

6. Remove the propeller shaft assembly (Figure 53)from the gear case.

NOTE: Reverse gear , sliding clutch , rollpin

and spring are removed as part of the propshaft assembly.

7. Pull the drive shaft (Figure 54) out (arrow) from

the pinion gear . Remove the pinion gear and the

forward gear/bearing assembly from the gear case.

Inspect all gears for wear or damage. Inspect the seal forthe shift shaft. If any gear is worn or damaged replace allgears as a set. Inspect the bearing on the forward gear. Ifthe bearing shows wear or damage inspect the bearing raceinside the gear case. If the bearing race is worn or damagedreplace the gear case. If the bearing is damaged replace thegear set.

Replace the drive shaft if it is bent, damaged or worn.

14

12

13

1110

98

4



3

Figure 52 — Remove Gear Case

Figure 53 — Gear Case Components

Figure 54 — Drive Shaft Components

7

11

48

9

12

10

6 13

12

14

32

8. Remove two stainless steel screws (Figure 55) and

stud from the input shaft carrier . Remove theinput shaft carrier assembly from the gear case.

Inspect shaft bushings inside the gear case. Inspect the seal

and the support for the gear selector shaft .Inspect the seal for the drive shaft. Inspect all lower unitparts for visual evidence of wear or damage. Replace o-rings

. Replace any worn or damaged parts.

Sliding Clutch1. Install the propeller shaft to Briggs & Stratton Tool

(#19555), Insert the tool knob (Figure 56)through the tool body and into the shaft to secure theshaft to the tool.

2. Insert the pin through the tool into the knob tosecure the knob to the tool.

3. With the shaft properly installed to the tool, remove

and discard the roll pin (Figure 56) from thesliding clutch. Disassemble the tool and the propellershaft/sliding clutch assembly.

Replace the shaft if it is bent or if the clutch splines areworn. Replace the roll pin. Inspect the sliding clutch andspring. Replace worn or damaged components.

4. Install the shaft, spring and sliding clutch to the tool.Assemble the shaft in reverse order.

3

1

2

20

211918

1716

15



3

Figure 56 — Tool (#19555)Figure 55 — Shifting Components

20

1

2

3

21

19

18

16

15

17

WARNING

The spring is under pressure. Usecaution when removing orinstalling the tool handle and thespring. Always wear eyeprotection.

CAUTION: Replace the roll pin wheneverit has been removed from the propellershaft. Damage to gear case componentscould result from a missing or mis-installedroll pin.

33

MidsectionDisassembly

1. Remove the nut from the opposite side of the

transom bracket bolt (Figure 57) . Remove thetransom brackets.

2. Remove four socket head screws .

3. Separate and remove the tilt brackets (Figure 58)from the midsection.

NOTE: The port side tilt bracket has the frictionbrake shoe for the steering. Do not lose the brake

shoe. The reverse hook may come off witheither tilt bracket.

4. Inspect the steering brake shoe and the reverse hook

actuator (Figure 58) . Replace if worn or damaged.

5. Remove and inspect the sleeves and rubber bushings

(Figure 59) & . Replace if worn or damaged.

NOTE: Be aware of the “stack-up” of bushing andsleeves.

21

4

5

3

2

1



3

Figure 57 — Remove Transom Brackets

Figure 58 — Remove Tilt Bracket

Figure 59 — Inspect Steering Bushings

1

2

3

45

3

1

1

2

2

34

Throttle CableReplacement

1. Pull the rubber grip (Figure 60) from the tiller

handle .

2. Remove the cap screws from the retainer .Remove the tiller assembly from the front handle.

3. Remove the isolators from the tiller handle.

4. Remove the throttle cable from the rod in thetiller handle. Pull the cable from the handle and out ofthe isolators.

NOTE: Grease the throttle rod support bracketinside the tiller handle whenever the tiller assemblyis serviced.

5. Installation is the reverse of removal. Torque capscrews to 45 in. lbs. (5 Nm).

Rewind Starter

NOTE: Rewind starters used on these modelseries engines are riveted to the blower housing.Replacement starters are supplied with screws andnuts to replace the rivets, when mounting newassemblies.

Remove Rope

1. Pull starter rope out as far as it will go.

2. While holding pulley and starter housing, pull pulleyend of rope out and untie knot at end of rope.

3. Remove rope and handle from starter.

4. Slowly release pulley to release spring tension.

Inspect Rope

1. Inspect rope. Replace if frayed or broken strands arefound.

2. If re-using old rope, burn each end of rope with anopen flame and wipe rope ends with waste cloth whilestill hot, to prevent swelling and un-raveling.

NOTE: When installing a new rope, check partslist to be sure correct diameter and length is used.The service replacement rope is cut to length asrequired.

Remove Pulley and Spring

1. Remove shoulder screw (Figure 61) and retainer

.2

1

26

4

85

1

3



3

Figure 60 — Throttle Cable Assembly

„

12

3

4

5

8

6

WARNING

Wear eye protection wheninstalling or removing starterpulley and spring. The starterspring is still under tension whenthe rope has been removed andthe pulley has been unwound.

35

2. Lift out pawls (Figure 61) .

3. Rotate pulley until pulley feels free.

4. Carefully lift out pulley with spring (Figure 62).

Inspect Spring, Starter Housing and Pulley

1. Inspect pulley for wear, cracks, rough edges

(Figure 63) or burrs in pulley groove and wear

on center hole .

2. Replace pulley if damaged or worn.

3. Inspect spring for broken ends, kinks and burrs.Replace assembly if any of the above conditions exist.

4. Inspect starter housing for wear or sharp edges at

rope eyelet (Figure 64) , center pivot post , and

inner spring anchor tab .

5. Replace assembly if worn or damaged.

4

65

3

21

3



3

Figure 61 — Rewind Starter Pulley

Figure 62 — Pulley With Spring

Figure 64 — Starter Housing

1

2

3

Figure 63 — Starter Pulley Spring

2

3

6

1

4

5

CAUTION: Pulley and spring is servicedas an assembly. Do not remove spring frompulley.

36



3

37

Section 4 • Overhaul


4Overhaul

Overhaul 37

Magnetron Ignition 39

Remove Armature 39

Inspect Valve Springs 39

Inspect Valve Guides 39

Finish Ream Valve Guides 39

Reface Valves and Seats 39

Remove Piston Rings 39

Check Piston Ring Groove Wear 40

Check Piston Ring End Gap 40

Check Connecting Rod 40

Undersized Connecting Rods 40

Check Piston Pin and Piston Pin Bore 41

Inspect Crankshaft 41

Inspect Camshaft 42

Check Cylinder 42

Cylinder Resizing 42

Set Up For Honing 42

Hone Cylinder 43

Cylinder Finish (“Cross Hatch”) 43

Cylinder Cleaning 44

Check Camshaft Bearings 44

Check Crankshaft Bearings 44

Remove DU™ Magneto Bearing 44

Install DU™ Magneto Bearing 45

Oil Seals 45

38



4

39

Magnetron IgnitionRemove Armature

The best means of testing Magnetron™ armatures is on theengine. Before replacing the armature, be sure that theproblem is not in the wiring, the safety/engine stop switch,the neutral switch or speed limiter.

Inspect Valve SpringsReplace broken, distorted or worn valve springs.

Inspect Valve Guides1. Check valve guides for wear using Reject Gauge Tool

(#19122).

2. If flat end of gauge can enter guide for 1/4" (6.35mm)or more, valve guide is worn. Replace the cylinderhead.

3. If plug gauge is not available, replace the cylinder headif the valve guide exceeds .267" (6.78mm).

Finish Ream Valve Guides

NOTE: The following procedure is recommendedto assure that the entire guide is clean and free offoreign material.

1. Use Finish Reamer Tool (#19096) and Reamer PilotGuide Tool (#19191) to remove foreign material orburrs from guide.

2. Use Stanisol® or kerosene to lubricate reamer.

3. Ream through entire guide.

4. Keep turning reamer clockwise when removingreamer.

5. Flush out all reaming chips.

Reface Valves and SeatsValve faces can be resurfaced using a commercially availablevalve grinding tool. Briggs & Stratton does not recommendthis practice as a high quality repair procedure. Valvereplacement is recommended for damaged or worn valves.

Valve seats (Figure 65B) are cut to 45° using Tool(#19237) or (#19343), “Neway Valve Seat Cutter Kit®”.Valve and seat are lapped in using Valve Lapping Tool(#19258) and Valve Lapping Compound (#94150) toassure a good seal between the valve face and the seat.

1. Thoroughly clean lapping compound from valve seatand valve face.

2. Valve seat width should be as shown (Figure 65B).

3. If seat is wider, a narrowing cutter should be used. Ifvalve face is badly burned, the burned valve should bereplaced.

4. Replace valve if margin (Figure 65A) is less than1/32" or is damaged.

5. Valve seat width should be 3/64 - 1/16". If the seatwidth is not within specification, or if the seats areburned or damaged, replace cylinder head.

Remove Piston RingsRemove piston rings using Piston Ring Expander (#19340)as shown (Figure 66).

NOTE: Some oil control rings consist of two thinsteel rails and a spring expander. The steel railscannot be removed with the piston ring expander.

2

1

2

OVERHAUL



4

Figure 65 — Valve & Seat Specifications

455� ‚

Figure 66 — Ring Expander

A B

1 2 45°

40

1. Grasp one end of the steel rail and wind the rail fromthe oil ring groove into the next ring groove.

2. Repeat into the top ring groove and then off thepiston.

Check Piston Ring Groove Wear1. Clean carbon from top ring groove.

2. Place a new ring (Figure 67) in groove andmeasure space between ring and ring land. If themeasurement is .007" (.18mm) or greater, reject thepiston.

Check Piston Ring End Gap1. Clean all carbon from the end of the rings, and from

the cylinder bore.

2. Insert old rings (Figure 68) one at a time one inchdown into the cylinder.

3. Check end gap with feeler gauge .

4. Replace the piston ring if the ring end gap is greaterthan:

Top Compression Ring .020 in. (.51mm)

Center Compression Ring .030 in. (.76mm)

Oil Control Ring .035 in. (.89mm)

Check Connecting RodIf the crankpin bearing is scored, the rod must be replaced.

Reject size of the crankpin bearing (Figure 69) is 1.102in. (27.99mm) or greater. Reject size of the piston pin

bearing is .627 in. (15.93mm) or greater.

Undersized Connecting RodsUndersized connecting rods .020" (.51mm) are available ifcrankpin is scored or worn below reject. Check illustratedparts list for part number availability.

1. Grind crankpin (Figure 70) to the followingdimensions:

2

1

4

3

2



4

Figure 68 — Ring End Gap

Figure 69 — Connecting Rod Bearings

Figure 67 — Measuring Ring Groove Wear

2

1

2

3

4

41

Crankpin diameter (A) 1.078 - 1.079 in.

(27.39 - 27-41mm)

Fillet Radius (R) .069 - .079 in. (1.75 - 2.01mm)

Crankshaft Throw (T) 1.020 in.

(25.91mm)

Check Piston Pin and Piston Pin BoreIf piston pin is worn .001" (.03mm) out of round, or if it isunder .624 in. (15.85mm), it should be replaced. Oversizepiston pins are available for some models. Check theillustrated parts list for part number availability.

Replace the piston if the piston pin bore (Figure 71) is.627 in. (15.93mm) or greater.

Inspect Crankshaft

1. Figure 72 shows wear points to be checked oncrankshaft. Discard crankshaft if worn smaller than thefollowing minimum diameter specifications. Mag

journal (Figure 72) .873 in. (22.17mm) PTO

journal 1.060 in. (26.92mm)

2. Resize the crankpin journal if worn smaller than the

following minimum diameter. Crankpin journal 1.097 in. (27.86mm)

3. Inspect keyway . Replace the crankshaft if thekeyways show wear or spreading. Remove burrs fromkeyway edges to prevent bearing damage.

4. Check timing gear for chipped or cracked teeth.Check the gear keyway for wear. Replace gear ifdamaged.

4

2

3

5

1

3



4

Figure 71 — Piston Pin Bore

Figure 72 — Crankshaft Wear Points

Figure 70 — Crankpin Dimensions

A

R

T

3

54

3

12

CAUTION: Always replace a bent crankshaft.

42

Inspect Camshaft1. Inspect gear teeth (Figure 73) . Replace the

camshaft if the teeth are worn or nicked.

2. Measure PTO journal , and mag journal .Replace the camshaft if either journal is worn smallerthan the reject dimensions below.

Mag Journal .498 in. (12.65mm)

PTO Journal .498 in. (12.65mm)

3. Inspect the camshaft lobes . Replace the camshaft ifthe lobes are worn or galled.

4. Replace camshaft if compression release binds,pivot pin is worn, or return spring is broken.

Check CylinderInspect cylinder whenever engine has been disassembled.Inspect for cracks, stripped boltholes, broken fins orcylinder wall damage. Use a Telescoping Gauge (#19485)with a Dial Caliper (#19199) to determine size of cylinderbore. Measure the cylinder bore at right angles, at the top

(Figure 74) , middle and bottom areas of thepiston ring travel . Standard cylinder bore is 2.688" (68.28mm). If the cylinder bore is more than .003" (.08mm) oversize, or .0015" (.04mm) out of round, it mustbe resized.

NOTE: New piston rings may be installed if thecylinder bore is within specification and shows nosign of scoring or other damage. When installing newpiston rings the cylinder bore should bereconditioned using a rigid hone with finishing stonesto restore the proper cross hatch angle in thecylinder bore.

Cylinder ResizingAlways resize bore to exactly .010", .020", or .030" (.25mm, .50mm or .76mm) over standard size. If this isdone accurately, the stock oversize rings and pistons will fitcorrectly, maintaining proper clearances. Cylinders can bequickly resized with a good quality hone set such as Briggs& Stratton Tool (#19205). Contact your Briggs & Strattonsource of supply. Use stones and lubrication recommendedby hone manufacturers to produce correct cylinder wallfinish. Honing can be done with a portable variable speed1/2" electric drill.

Set Up For Honing

Check cylinder bores at top and bottom for burrs. Removeburrs to prevent damage to hone. Fasten cylinder to a honing fixture such as a 2" X 6" (51mm X 152mm)

piece of wood approximately 16" (406mm) long. Clamp thecylinder and honing fixture in a vise at a convenient workingheight.

321

2

3

5

4

45

1



4

Figure 73 — Camshaft

Figure 74 — Cylinder Measurements

4

1

2

3

3

1

2

5

43

Hone Cylinder

1. Place hone in middle of cylinder bore. Tightenadjusting knob with finger or small screwdriver untilstones fit snugly against cylinder wall. Do not force.

2. Install drive shaft to drill chuck. Connect drive shaft tohone. Be sure that cylinder and hone are centered andaligned with drive shaft and drill spindle.

3. Lubricate honing stones and cylinder bore with honingoil or automatic transmission fluid.

Recommended drill speed is 300-700 RPM maximum and 40-60 strokes per minute. Lubricate hone frequently toprevent build-up on stones. The cylinder will show the most

wear in the ring travel area (Figure 75) . The cylinderdoes not wear oversize or out-of-round below the ring

travel area and will guide the hone to straighten cylinderbore.

4. Start the drill and, as the hone spins, move it up anddown limiting the travel to the bottom of the cylinder

(Figure 75) .

5. As the bottom of the cylinder increases in diameter,gradually increase the length of the strokes until honetravels full length of bore and extends past the

cylinder bore ends .

Do not extend hone more than 3/4 - 1" (19mm - 25mm) at

either end of cylinder bore .

6. As cutting tension decreases, stop hone and tightenadjusting knob.

7. Check cylinder bore frequently with an accuratemicrometer.

Cylinder Finish (“Cross Hatch”)The finishing stones are used after the cylinder bore hasbeen resized to within .0015" (.04mm) of the desired sizeor when reconditioning a cylinder bore. The finishing stonesproduce the correct cross hatch necessary for properlubrication. Correct cross hatch angle is approximately 45degrees (Figure 76).

It is recommended that the cylinder bore be reconditionedto restore the cross hatch when new piston rings are to beinstalled to a cylinder that is within specification. Do nothone oversize or it will be necessary to resize the cylinder.

NOTE: To produce the proper cross hatch finishuse a drill speed of approximately 200 RPM and 40-60 strokes per minute. Lubricate hone liberally toprevent build up on finishing stones.

4

4

3

2

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4

Figure 75 — Cylinder Honing Details

C

B

Figure 76 — Cylinder Finish

1

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44

Cylinder CleaningIt is most important that the entire cylinder and crankcasebe thoroughly cleaned after honing.

First, wash the cylinder and crankcase carefully in solventsuch as kerosene or commercial solvent. Then thoroughlywash cylinder and crankcase using a stiff brush with soapand hot water. Rinse thoroughly with hot running water.Continue washing and rinsing until all traces of honing gritare gone. Honing grit is highly abrasive and will cause rapidwear to all internal components of the engine unless it iscompletely removed.

NOTE: When the cylinder and crankcase havebeen thoroughly cleaned, use a clean white rag ornapkin and wipe the cylinder bore. If honing grit ispresent it will appear as gray residue on the rag. Ifany honing grit is evident, re-wash and rinse theentire cylinder and crankcase, and check again. Whenthere is NO trace of honing grit on the rag thecylinder is properly cleaned.

Check Camshaft BearingsReplace cylinder or sump if cam gear bearings are wornmore than specification. Replace cylinder or sump if PlugGauge (#19164) can be inserted in bearing 1/4" (6.35mm)or more (Figure 77).

If gauge is not available, replace cylinder or sump if bearingsare worn over .503" (12.78mm).

Check Crankshaft BearingsCheck the crankshaft bearings in the cylinder and sumpwhenever the engine is apart. Gauge or measure at severallocations in bearing. Check the Mag bearing with PlugGauge (#19166) as shown (Figure 78).

If no plug gauge is available, use .877" (22.28mm) as thereject dimension. Replace the bearing if it exceeds thereject dimension. Check the PTO bearing with Plug Gauge(#19375). If no plug gauge is available use 1.0655"(27.06mm) as the reject dimension. Replace the sump if itexceeds the reject dimension.

Remove DU™ Magneto Bearing1. Place Briggs & Stratton Cylinder Support Tool

(#19123) (Figure 79) under magneto bearing .

Place Briggs & Stratton Bushing Driver (#19124)down through worn bearing.

2. Press bearing out of cylinder.

1

23



4Figure 77 — Plug Gauge (#19164)

Figure 78 — Check Crankshaft Bearing

45

Install DU™ Magneto Bearing1. Place DU bearing on cylinder with bearing oil hole in

line with oil hole in cylinder.

2. Use Briggs & Stratton Bushing Driver Tool (#19124)

(Figure 80) to press bearing to a depth of.080" (2.03mm). Measure from thrust face side ofcylinder.

3. Stake bearing to cylinder as shown (Figure 81).

Oil SealsInstall new oil seals whenever engine is disassembled. Wheninstalling crankcase cover or sump, always use the correctseal protector to prevent damaging oil seal.

32



4

Figure 79 — Remove DU™ Magneto Bearing

Figure 80 — Install DU™ Magneto Bearing

Figure 81 — Stake Cylinder Bearing

1

2

3

2

3

46



4

47

Section 5 • Assembly


5Assembly

Assembly 47


Piston Rings 49

Compress Piston Rings 49

Crankshaft Installation 50

Install Connecting Rod & Piston 50

Install Camshaft 51

Install Sump 51

Crankshaft End Play 51

Install Flywheel 52

Install Armature 52

Armature Air Gap 52

Cylinder Head Assembly 53

Install Cylinder Head Plate and Rocker Arm Studs 53

Install Valves 53

Install Valve Springs and Retainers 53

Install Cylinder Head 54

Install Rocker Arms 54

Adjust Valve Clearance 55

Install Valve Cover 55

Carburetor Assembly 55

Install Welch Plug 55

Install Choke Shaft 56

Install Throttle Shaft 56

Install Inlet Needle and Float 56

Install Carburetor 57

Install Pulley and Spring 57

Install Pawls, Pawl Springs & Retainer Assembly 58

Wind Spring & Install Rope 58

Install Blower Housing 59

Gear Case Assembly 59

Mid Section Assembly 62

Install Power Head 63

Cooling Shroud Installation 64

Adjust Throttle Cable 64

Idle Adjustment 65

48



5

49

Piston and Connecting RodThe piston pin is a slip fit in both the piston and connectingrod.

1. Oil the piston pin. Assemble the piston to theconnecting rod as shown in.

NOTE: The word MAG cast in the flywheel side ofthe connecting rod must face the same direction as

the arrow (Figure 82) on top of the piston.

2. Insert the piston pin from the piston pin lock side of

the piston pin bore until the pin stops against theshoulder.

3. Install the piston pin lock. Be sure lock is firmly set ingroove.

Piston RingsCorrect piston ring positions are shown.

1. Install the expander (Figure 83) and oil control

ring first, followed by the center ring and top

ring .

2. Install the center and top rings with the ID mark facing the top of the piston.

Compress Piston Rings

1. Oil the piston rings and piston skirt.

2. Compress the piston rings with Ring Compressor(#19230) (Figure 84).

3. Place piston and compressor upside down on benchand push piston down until head of piston is even withedge of compressor.

4. Tighten compressor until piston cannot be turned.

5. Loosen compressor until piston can be turned withslight resistance (Figure 85).

NOTE: Do not attempt to install piston and ringassembly without ring compressor.

5

1

23

4

2

1

ASSEMBLY



5Figure 83 — Piston Rings

Figure 84 — Ring Compressor

Figure 85 — Piston Assembly Ready To Install

Figure 82 — Piston & Rod Assemblies

1

2

3

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5

5

1

2

50

Crankshaft Installation1. Select a seal protector based on size of crankshaft

mag journal.

2. Insert protector into mag side oil seal.

3. Install crankshaft to cylinder.

4. Install slip fit timing gear (if removed) with timingmark out.

Install Connecting Rod & Piston1. Lubricate cylinder bore and crankpin.

2. Rotate crankshaft until crankpin journal is at bottomof stroke.

NOTE: This permits the compressed rings, pistonand rod assembly to be pushed into the cylinder.

3. Install piston with arrow (Figure 86) towardflywheel side of engine. Take care not to damagecrankpin journal or connecting rod journal.

4. Pull connecting rod against crankpin.

5. Install connecting rod cap with notch in rod capaligned with tab in connecting rod.

NOTE: The notch in the connecting rod cap

(Figure 87) must engage the tab on the

connecting rod .

6. Install connecting rod cap screws.

NOTE: Torque the screw closest to the piston

(Figure 88) first. Torque the screw farthest from

piston second . The connecting rod screws mustbe torqued in this sequence.

5

4

2

3

1



5

Figure 86 — Install Piston Assembly

Figure 88 — Torque Connecting Rod Cap

Figure 87 — Connecting Rod Cap

23

4

5

1

4

5

CAUTION: Failure to use a torquewrench can result in loose rods (causingbreakage) or over-tightened rods (causingscoring).

5

51

7. Use Torque Wrench (#19393) to torque connectingrod cap screws to 100 in. lbs. (11 Nm).

8. Rotate crankshaft two revolutions to make surecrankpin and rod are not binding during rotation.

9. Move connecting rod sideways to be sure rod slidesfrom side-to-side.

Install Camshaft1. Install tappets. Be sure tappets clear cam lobes.

2. Install camshaft.

Timing marks (Figure 89) must be aligned. Typicalalignment is shown.

3. Assemble oil slinger to camshaft.

Install Sump1. Install sump using seal protector. Do not force sump.

2. Install screws, torque in sequence as shown (Figure 90). Torque to 110 in. lbs. (12 Nm).

Crankshaft End PlayWhen sump is installed with a standard gasket, end playshould be .002-.028 in. (.05-.71mm). Always measure endplay with a standard gasket in place. If end-play is more thanspecification, replace crankcase cover or sump, or use

(#220624) shim (Figure 91) on magneto end ofcrankshaft. If end play is less than specification use

additional gasket(s) (Figure 92) between the sump

and the cylinder to get proper end play.4

23

1

1



Figure 89 — Camshaft Timing Marks

Figure 90 — Torque Sump Cover

Figure 91 — Crankshaft End Play

1

2

5

46

1

1

7

3

52

Install Flywheel

1. Clean flywheel taper and crankshaft taper,removing all oil, dirt or grease.

2. Install flywheel key to slot before installing flywheel.

3. Slide flywheel onto crankshaft.

4. Torque flywheel nut to 60 ft. lbs. (80 Nm).

Install Armature1. Install stop switch wire to armature.

2. Turn flywheel so magnet (Figure 93) is away fromcoil. Install armature assembly on engine.

3. Install coil mounting screws finger tight.

Armature Air Gap1. Pull left side of armature away from flywheel and

tighten left screw.

2. Rotate flywheel until magnet is under armaturelaminations.

3. Place thickness gauge blade (Figure 94) betweenmagnet and armature.

NOTE: Use a .010-.014" (.25-.36mm) gauge.

4. Loosen left armature screw and let magnet pullarmature down onto flywheel magnet. Torque screwsto 25 in. lb. (3 Nm).

3

2

1



5

Figure 92 — Shimming The Crankcase Cover

Figure 93 — Armature

Figure 94 — Setting Armature Air Gap

3

4

2

1

2

3

WARNING: Do not use impact wrenchesto install flywheel.

5

53

Cylinder Head AssemblyInstall Cylinder Head Plate and Rocker Arm Studs

1. Place new cylinder head plate gasket and cylinder headplate on cylinder head.

NOTE: The cylinder plate is labeled for correctinstallation.

2. Install two rocker arm studs (Figure 95) . Torqueto 80 in. lbs. (9 Nm).

Install Valves

NOTE: A valve stem seal (Figure 96) is usedon the intake valve.

1. Valve sticking will occur and valve stem seals will bedamaged if the stems and guides are not free offoreign material and burrs.

2. Lightly coat valve stems with Valve Guide Lubricant(#93963) and install in valve guides.

3. Oil the inside diameter of the valve stem seal withengine oil and install on the valve stem.

4. Slide seal down against head plate.

NOTE: Be sure Valve Guide Lubricant is not onvalve face, valve seat or exposed end of valve stem.

Install Valve Springs and Retainers1. Place a shop rag or wood blocks on work surface to

support valves. Place cylinder head on rag or blocksand install valve spring over valve stem.

2. Place retainer (Figure 97) on spring. Depressretainer with thumbs to compress spring.

1

2

1



Figure 97 — Valve Spring Retainers

Figure 96 — Valve Stem Seals

Figure 95 — Cylinder Head Plate

1

1

2

54

3. Compress spring until valve stem extends throughlarge end of retainer slot. Continue to press untilsmall end of slot can slide into groove on valve stem.Be sure retainer is fully engaged to valve stem groove.

Install Cylinder Head

NOTE: Do not use sealer on gaskets.

1. Coat threads of cylinder head screws with ValveGuide Lubricant (#93963).

2. Place new cylinder head gasket on dowel pins andthen install cylinder head and cylinder head screws.

3. Torque screws in sequence as numbered on cylinderhead, or as shown (Figure 98). Tighten the cylinderhead in three steps:

NOTE: Do not tighten any screw to the finaltorque before all screws have been tightened to thesecond step. Uneven tightening may cause a warpedcylinder head.

First step: 70 in. lbs. (8 Nm)

Second step: 140 in. lbs. (16 Nm)

Final step: 210 in. lbs. (24 Nm)

Install Rocker Arms1. Install push rods (Figure 99) through push rod

guide making sure push rods are in valve tappets .

2. Remove all lubricant from end of valve stems.

3. Place valve caps (Figure 100) on end of valvestems. Do not use lubricant on the valve caps.

4. Place rocker arms on studs and install rocker arm

adjusting nuts and set screws while holding rockerarm against valve cap and pushrod until nut is fingertight.

5. Rotate crankshaft at least two revolutions to be surepush rods operate rocker arms.

4

3

2

1



5

Figure 98 — Torque Cylinder Head Bolts

Figure 99 — Install Rocker Arms

‚

Figure 100 — Valve Caps & Adjusting Nuts

1

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3

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32

4

5

55

Adjust Valve ClearanceCheck valve clearance while engine is cold.

1. Turn crankshaft until piston is at TDC of thecompression stroke.

2. Insert a narrow screwdriver or small rod into sparkplug hole against the piston. The screwdriver or rod isused to gauge piston movement.

NOTE: Correct positioning of crankshaft isrequired to prevent compression release fromholding valves open.

3. While watching screwdriver or rod, turn crankshaftclockwise (flywheel end) past TDC until piston is 1/4"(6.35 mm) down.

4. Using feeler gauges (Figure 101) , check valveclearance. Clearance should be .004 - .008" (.10 - .20mm) for intake and exhaust valves.

5. To adjust, loosen set screw (Figure 102) . Turn

rocker nut until valve clearance is correct.

6. When valves are adjusted, hold rocker nut. Tightenset screw to 35 in. lbs. (4 Nm).

7. Recheck clearance and adjust, if required.

Install Valve Cover1. Install valve cover with new gasket. Install four screws.

Torque screws to 85 in. lbs. (10 Nm).

2. Install muffler, exhaust manifold, air guides, shields andother parts removed from cylinder head.

3. Torque muffler screw to 85 in. lbs. (10Nm).

Carburetor AssemblyInstall Welch Plug

Install welch plug (Figure 103) with a pin punch slightly smaller than the outside diameter of the plug.

21

2

1

3



Figure 101 — Checking Valve Clearance

Figure 102 — Adjusting Valve Clearance

Figure 103 — Install Welch Plug

3

1 2

2

1

56

2. Press in until plug is flat. Do not cave in plug.

3. After plug is installed, seal outside edge of plug withfingernail polish or non-hardening sealant.

Install Choke Shaft

1. Install choke shaft (Figure 104) and felt washer . Rotate choke shaft until lever is as shown.

2. Insert and center choke plate in slot of choke

shaft, with dimples as shown.

Install Throttle Shaft

1. Install throttle shaft (Figure 105) and foam washer

.

2. Turn shaft until flat is facing out.

3. Lay throttle plate on shaft with numbers facing out

and install screw .

Install Inlet Needle and Float

1. Install inlet needle (Figure 106) to float andinstall assembly to carburetor body.

2. Insert float hinge pin and center pin between floatpin bosses. Float height is non-adjustable.

3. Install rubber gasket on carburetor and lay float bowlon body.

4. Place fiber washer over main jet and installmain jet. Torque nut to 50 in. lbs. (6 Nm).

12

3

45

4

1

3

2

4

3

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5

Figure 104 — Choke Shaft

Figure 105 — Throttle Shaft

Figure 106 — Assemble Carburetor

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5

57

Install Carburetor1. Place a new intake gasket (Figure 107) between

the control bracket and the cylinder head.

2. Place a new intake gasket between the control

bracket and the carburetor .

3. Using carburetor mounting screws to align parts,place carburetor and gasket on control bracket.

4. Install carburetor assembly to the cylinder head with

two mounting screws . Torque screws to 90 in. lbs. (10 Nm).

NOTE: Use new screws or Locktite sealant toprevent screws from vibrating loose.

5. Install a new air horn gasket and the air horn tothe carburetor.

6. Install fuel pump and connect fuel lines.

7. Install speed limiter.

Install Pulley and Spring1. Lay starter housing on workbench.

2. Assemble starter pulley (Figure 108) to center

pivot post in housing.

3. Rotate pulley counterclockwise until slight resistanceis felt, indicating that spring is engaged in spring tab(Figure 109).

2

1

2

1

1

35

4

5

6



Figure 107 — Carburetor Installation

Figure 108 — Starter Pulley

1

12 3

4 56

1

2

Figure 109 — Engage Pulley Spring

58

Install Pawls, Pawl Springs &Retainer Assembly

1. Install pawls (Figure 110) .

2. Install retainer (Figure 111) making sure that slots

in retainer engage tabs on pulley.

3. Hold retainer down, compressing pawl springs and

install retainer screw. Torque screw to 70 in. lbs. (8 Nm).

4. While holding retainer, rotate pulley to extend andretract pawls. If the pawls do not extend and retract,remove retainer and reinstall.

Wind Spring & Install Rope1. Tie knot on one end of the rope.

NOTE: Knot must be the original "Figure 8" style,(Figure 112) so it will not pull through pulley orrope handle hole.

2. Turn pulley counterclockwise until spring is woundtight.

3. Rotate pulley clockwise until rope hole (Figure 113)

in pulley is in line with starter housing eyelet and hold pulley.

4. Insert unknotted end of rope through rope hole inpulley, then through eyelet in housing.

21

4

63

5

2



5

Figure 111 — Rewind Assembly

Figure 113 — Rope Installation

Figure 112 — Rope Knot

Figure 110 — Install Pawls

2

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59

5. Pull rope until knot rests against pulley.

6. Tie a temporary knot (Figure 114) in the rope toprevent the rope from retracting into the pulley.

7. Let pulley and spring slowly retract rope againsttemporary knot.

Install Blower Housing1. Install blower housing (Figure 115).

2. Torque screws to 85 in. lbs. (10 Nm).

Gear Case Assembly1. Install the shift cam/rod (Figure 116) to the gear

case .

2. Install the shift shaft support with seal and the

O-rings to the input shaft carrier.

3. Install the input shaft carrier to the gear case.

Torque stainless steel screws and stud to 55 in. lbs. (6 Nm).

18

7

4

23

6

5

4



Figure 114 — Securing Rope

Figure 116 — Gear Case

Figure 115 — Blower Housing

1

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8

6

4

A B

60

4. Install the forward gear and bearing assembly

(Figure 117) to the housing.

5. Install the pinion gear to the recess in the gearcase.

NOTE: The shift cam must be in theFORWARD position when assembling the propellershaft assembly to the gear case (inset).

6. Install the shift cam follower to the propeller shaft

assembly . Install the propeller shaft assembly andcam follower to the gear case.

7. Assemble reverse gear (Figure 118) to the carrier

.

8. Apply Anti-Seize to the carrier threads.

9. Install the carrier assembly to the gear case and alignall gears. Hand tighten the carrier until the flangecontacts the face of the gear case. Do not torque thecarrier at this time.

The carrier is Left-Hand-Thread.

NOTE: It may be necessary to turn the drive shaftand/or the propeller shaft to mesh gears.

10. Install the drive shaft through the top plate into thepinion gear.

11. Depress the shift cam/rod (Figure 119)approximately 5/16" (8 mm) to select NEUTRAL.

NOTE: Turn the drive shaft and/or the propellershaft to verify NEUTRAL.

12. Install the clamp (Figure 120) to the shiftcam/rod. Tighten the clamp just enough to locate theclamp to the rod.

16

5

14

15

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11

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5

Figure 117 — Install FORWARD Gear

Figure 118 — Assemble REVERSE Gear

Figure 119 — Install Carrier Assembly

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15

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14

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5

IMPORTANT: The locating ridges of the clamp mustengage the slot in the rod.

13. Place the shift selector in NEUTRAL.

14. Slide the upper shift rod (Figure 121) into the

clamp as you place the gear case onto themidsection.

15. Install the gear case assembly to the midsection.

Torque the screw (Figure 122) to 60 in. lbs.

(7 Nm). Torque the nut to 80 in. lbs. (9 Nm).

16. Verify that the gear lever and gear case are both inNEUTRAL, and that the shift rod and shift cam/rodare both engaged to the clamp. Tighten the clampthrough the hole in the gear case (Figure 123).Torque the clamp screw to 35 in. lbs. (4 Nm).Again verify NEUTRAL.

17. Use Briggs & Stratton Socket (#19557), to torquethe carrier to the gear case. Torque the carrier to120 ft. lbs. (160 Nm).

18

19

16

17

Figure 120 — Shift Clamp

Figure 121 — Shift Rod Assembly

Figure 122 — Install Gear Case

Figure 123 — Tighten Shift Clamp

16

16

17

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62

NOTE: Always torque the carrier with the gearcase attached to the midsection (Figure 124).

18. Apply Anti-Seize to the propeller shaft threads.Install the propeller, stainless steel washer andstainless steel lock nut to the propeller shaft. Torquethe lock nut to 90 in. lbs. (10 Nm).

Mid Section Assembly

1. Apply Anti-Seize to the mounting surfaces of the

sleeves (Figure 125) . Place the sleeves and rubber

bushings together on the midsection.

2. Insert brake shoe (Figure 126) to port side tilt

bracket .

3. Locate reverse hook to port side tilt bracket with

pin .

4. Place the tilt bracket with the reverse hook onto themidsection. Align the bushings already in position onthe mid section (Figure 125) with the grooves in the

tilt brackets (Figure 126) .

5. Place the remaining tilt bracket onto the midsection.

6. Secure the tilt brackets with four (Figure 127)screws . Torque screws to 55 in. lbs. (6 Nm).

7. Install the transom brackets to the tilt brackets. ApplyAnti-Seize to the transom bracket bolt. Torque the

transom bracket nut (Figure 127) to 190 in. lbs (21 Nm).

1

2

5

9

8

7

6

2

1



5

Figure 126 — Brake Shoe

Figure 125 — Sleeves & Bushings

Figure 124 — Torque Carrier

1

2

1

2

5

5

7

89

6

5

63

8. The reverse hook actuator (Figure 128) isadjusted with a setscrew that is accessed through an

opening in the starboard tilt bracket. Adjust theactuator so that it just touches the reverse hookwhen NEUTRAL is selected. Tighten by turning theset screw clockwise. Verify correct adjustment.

NOTE: When correctly adjusted the bottom edgeof the reverse hook is at a right angle to the edge ofthe swivel bracket castings when REVERSE isselected.

Install Power Head

1. Grease the shift lever pockets under the neutral

switch (Figure 129) and the shift lever retaining

plate . Grease the hex end of drive shaft and

spring as shown.

2. Torque screws to 35 in. lbs. (4 Nm).

3. Connect the neutral switch wire to the wiringharness. Lower the power head onto the midsection.Align the hex socket in the crankshaft adapter to the

hex end of the drive shaft . Be certain that the wirefor the neutral switch is not pinched between thepower head and the midsection.

4

2

5

43

1

11

10



Figure 127 — Transom Bracket

Figure 128 — Reverse Hook

Figure 129 — Install Power Head

11

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64

4. Secure the power head to the midsection with twobolts on the port side and one bolt on the starboardside of the power unit (Figure 130). Apply Anti-Seizecompound to the threads of the bolts. Install the boltsthread--end up through the midsection and powerunit. Install the washers and nuts to the bolts. Torquethe nuts to 210 in. lbs. (24 Nm).

NOTE: The bolts must be installed from thebottom, with the threaded end up. The washers andlock nuts are installed from the top.

5. Connect the throttle cable to the carburetor. Securein position with the throttle cable clamp. Replace thewire ties that hold the throttle cable to the rearhandle.

6. Connect the choke control rod to the choke lever.

Cooling Shroud Installation1. Insert the starter rope through the opening in the

shroud.

2. Pull the rope through the openings in the handle andhandle insert.

3. Knot the end of the rope with a figure 8 knot

(Figure 131) as shown.

4. Pull the handle out and hold.

5. Remove temporary knot.

6. Install the shroud, safety/engine stop switch, dipstickand top cover.

Adjust Throttle Cable1. With throttle control in the IDLE position, loosen

casing clamp screw (Figure 132) at the back of theoutboard.

2. Push the throttle cable toward the carburetor controlbracket to move the throttle to the idle stop.

1

1



5

Figure 132 — Adjust Throttle Cable

Figure 130 — Secure Power Head

Figure 131 — Pull Handle Assembly

1

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5

65

3. Press on the throttle to ensure that it is seated firmlyagainst the idle adjusting screw.

4. Snug the casing clamp screw. Observe the range ofthrottle motion when the hand grip is moved fromIDLE to HIGH SPEED stops.

Idle Adjustment1. Start and run the engine at half throttle to warm

engine to operating temperature.

2. Rotate throttle lever counterclockwise to the IDLEposition and hold against throttle stop while adjusting

idle speed adjusting screw (Figure 133) to obtain1900 RPM (1400 RPM in FORWARD gear, with thepropeller in water).

3. Move throttle control to FAST position. Engineshould accelerate smoothly.

4. Turn the idle mixture screw clockwise slowly untilthe engine just begins to slow, and note or mark theposition of the screw.

5. Then turn the screw counterclockwise until theengine just begins to slow. Again note or mark theposition of the screw.

6. Turn the idle mixture screw to the midpoint betweenthe two positions.

7. Install the limiting cap (Figure 134) to the idlemixture screw.

8. Move throttle control to FAST position. Engineshould accelerate smoothly. If the engine does notaccelerate smoothly, open the idle mixture screw 1/8turn.

3

2

1



Figure 133 — Idle Adjustment

Figure 134 — Limiting Cap

3

1

2

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5

67

Section 6 • Appendix


6Appendix

Appendix 67

Outboard Engine Fastener Specifications 68

Lower Unit Fastener Specifications 68

Ignition System Wiring Diagram 69

Component Location - Gear Case 71

Component Location-Midsection 73

68

APPENDIX



6

Outboard Engine Fastener SpecificationsBlower Housing 3/8" 85 in. lbs. (10 Nm)

Carburetor 3/8" 80 in. lbs. (9 Nm)

Connecting Rod 5/16" 100 in. lbs. (11 Nm)

Cylinder Head Bolt 3/8" 210 in. lbs. (24 Nm)

Muffler (to Cylinder Head) 3/8" 85 in. lbs. (10 Nm)

Flywheel 15/16" 60 ft. lbs. (80 Nm)

Ignition Armature 1/4" 25 in. lbs. (3 Nm)

Intake Air Horn 5/16" 45 in. lbs. (5 Nm)

Oil Drain Plug 3/8" Square Drive (internal) 125 in. lbs. (14 Nm)

Rocker Arm Ball Set Screw 1/8" Hex Drive (internal) 60 in. lbs. (7 Nm)

Spark Plugs 5/8" 180 in. lbs. (20 Nm)

Sump 1/2" 110 in. lbs. (12 Nm)

Throttle Plate Retaining Screw 2 45 in. lbs. (5 Nm)

Valve Cover 3/8" 85 in. lbs. (10 Nm)

Lower Unit Fastener SpecificationsCasing Clamp (Cylinder) 1 35 in. lbs. (4 Nm)

Choke Nut 1 30 in. lbs. (3 Nm)

Clamp Bracket Screw 2 35 in. lbs. (4 Nm)

Cowl Mounting Screw (10--32) 4 25 in. lbs. (3 Nm)

Cowl Screw Standoff 4 35 in. lbs. (4 Nm)

Cowl Cover Screw (10--24) 4 25 in. lbs. (3 Nm)

Engine Mounting Bolts 3 210 in. lbs. (24 Nm) *

Front Handle Casing Clamp Screw 1 35 in. lbs. (4 Nm)

Front Handle Screw 1 55 in. lbs. (6 Nm)

Front Handle Tiller Housing Pivot Cap 2 45 in. lbs. (5 Nm)

Rear Case/Midsection Nut 1 80 in. lbs. (9 Nm)

Gear Case/Midsection Self-Tapping Screw 1 60 in. lbs. (7 Nm)

Ground Wire Screw 1 90 in. lbs. (10 Nm)

Handle Screw 4 55 in. lbs. (6 Nm)

Hook Actuator Set Screw 1 35 in. lbs. (4 Nm)

Input Shaft Carrier-to-Gear Case Screw 2 55 in. lbs. (6 Nm)

Oil Drain/Fill Plug 1 45 in. lbs. (5 Nm)

Oil Vent Plug 1 20 in. lbs. (2 Nm)

Output Shaft Nut 1 130 in. lbs. (15 Nm)

69

Propeller Nut 1 90 in. lbs. (10 Nm) *

Reed-Switch Screw. 1 35 in. lbs. (4 Nm)

Safety/Engine Stop Switch 1 20 in. lbs. (2 Nm)

Shift Lever Screws 4 35 in. lbs. (4 Nm)

Shift Rod Clamp Screw 1 35 in. lbs. (4 Nm)

Shift Rod to Shift Cam Screw 1 20 in. lbs. (1 Nm)

Stud Mount Screw-to-Gear Case 1 55 in. lbs. (6 Nm)

Tilt Bracket Screws 4 55 in. lbs. (6 Nm)

Transom Thru--Bolt Clamp Nut 1 190 in. lbs (21 Nm) *

* Apply Anti--Seize compound to threads of these fasteners.

Always use Anti-Seize compound on any external screws and nuts that are stainless-to-stainless.

Ignition System Wiring Diagram



6

Ignition System

1. Safety/Engine Stop Switch

2. BLACK Wire -- to Safety/Engine Stop Switch

3. Connector

4. BLACK Wire -- Armature Ground

5. Armature

6. Spark Plug

7. BLACK Wire -- to Speed Limiter

8. Not Used

9. Neutral Switch

10. FORWARD Position

11. NEUTRAL Position

12. REVERSE Position

13. BLACK Wire

14. Wiring Harness Connector - to Engine Speed Limiter

15. WHITE Wire

16. Engine Ground

17. RED Wire

111 2

3 4

5

78

9

6

1213

14151617

10

70



6

Component Location — Gear Case

11

12

34

57

8

9

6

12

13

14

15

16

17

18

19

20

22

23

21

10

71

Component Location - Gear Case

1. Seal

2. Propeller Shaft Carrier(LH Thread)

3. O-Ring

4. Reverse Gear

5. Propeller Shaft

6. Spring

7. Sliding Clutch

8. Roll Pin

9. Vent Plug

10. Screw (2, SS)

11. Seal

12. O-Ring

13. Pinion Gear

14. Stud

15. Input Shaft Carrier

16. Quad Ring Seal

17. Seal

18. O-Ring

19. Shift Cam/Rod

20. Gear Case

21. Oil Drain/Fill Plug

22. Forward Gear/ Bearing Assembly

23. Shift Cam Follower



6

72



6

Component Location — Midsection

11

1

23

4

57

8

9

6

12

13

1415

16

17

18

19

20

21

22

23

10

73

Component Location-Midsection

1. Shift Lever

2. Shift Lever Handle

3. Plate

4. Screw (5 used)

5. Upper Shift Rod

6. Housing

7. Tilt Bracket(LH - Port)

8. Brake Shoe

9. Washer

10. Washer

11. Lock Nut

12. Transom Bracket

13. Clamp/Handle

14. Washer

15. Screw

16. Actuator

17. Reverse Hook

18. Pin

19. Bolt

20. Sleeve

21. Bushing

22. Tilt Bracket(RH -- Starboard)

23. Neutral Switch



6

74



6

Documents

Outboard Repair Manual E-Book_275110 BRIGGS & STRATTON