K15/21/25 Gasoline Engine Service Manual # 99789-75100

K15/21/25 Gasoline Engine

Service Manual # 99789-75100

The following modules do not cover all of the material in the manual. We have identified and chosen some of the more important key points. To

fully understand the engine in more depth you will need to read the

manual. More hands on work with the lift truck, and real life work will

improve your overall knowledge of this equipment.

Introduction

Engine Models and Fuel Type

Engine Type Engine Control System

K15

Carburetor Specification (Gas/LPG)

Electronic Controlled (Gas/LPG)

K21



K25



External View (Carburetor type)

External View (Electronic Type)

Indication of Model and Number

K15 Engine Specification

Current

Engine Model ４Ｇ１５

Engine Control Carburetor

Fuel Type Gasoline Dual Gasoline Dual Dual

Total Displacement (cc) 1468

Combustion Chamber Type Semi-spherical

Valve Mechanism ＯＨＣ

Bore × Stroke (mm) 75.5×82

Compression Ratio 9.4

Compression Pressure (Mpa｛kgf/c㎡｝ /rpm）

1.2｛12.0｝ /250

Ｋ１５

Electronic Control Carburetor

New

9.0

1.3｛13.0｝ /250

1486

Bath tub

ＯＨＶ

75.5×83


Current

４Ｇ１５

Carburetor

Gasoline Dual Gasoline Dual Dual

Max Output (kW｛PS｝ /rpm）24.9｛33.8

｝ /260022.9｛31.2

｝ /2600 （30） /2400

Max Torque Ｎ ‐ m｛kgf‐ m｝ /rpm100.0｛10.2｝ /1600

95.1｛9.7｝/1600

（9.7） /1600

600～650

2550～2600

Universal Joint

2800 2900

Fuel Type

Engine Control

New

On Vehicle Idle Speed （ rpm）

On Vehicle High-Idle Speed (rpm）

27.2｛37}/ 2600

104.9｛10.7｝ /1600

ＰＴＯ Type

Ｋ１５


Silent Chain Drive/Side ＰＴＯ Method

700 700

Engine Model


Current

Engine Model ４Ｇ６３



Total Displacement (cc） 1997



Bore × Stroke (mm） 85×88



1.1｛11.5｝ /300

8.7

1.2｛12.5｝ /250

89×83

Ｋ２１


New

2065

Bath Tub

ＯＨＶ


Current

Engine Model ４Ｇ６３




｝ /260033.1｛45.0

｝ /2600 （39） /2400

Max Torque Ｎ ‐ m｛kgf‐ m｝ /rpm142.2｛14.5

｝ /1600139.3｛14.2

｝ /1600（13.7） /1600

On Vehicle Idle Speed （ rpm） 600～650On Vehicle High-Idle Speed

（ rpm）2600～2650

ＰＴＯ TypeUniversal

Joint

New

Ｋ２１


Silent Chain Driven/Side PTO Method

2700 2750

38.2｛51.9｝ /2600

151.0｛15.4｝ /1600

700 700


Current

Engine Model ４Ｇ６４



Total Displacement (cc） 2350



Bore × Stroke （mm） 86.5×100



1.1｛11.5｝ /300

89×100

8.7

1.2｛12.5｝ /250

New

2488

Bath Tub

ＯＨＶ

Ｋ２５



Current

Engine Model ４Ｇ６４




｝ /240036.2｛49.3

｝ /2400 （50） /2400

Max Torque Ｎ ‐ m｛kgf‐ m｝ /rpm176.5｛18.0｝ /1600

171.6｛17.5｝ /1600

（17） /1600

On Vehicle Idle Speed

（ rpm）600～650

On Vehicle High-Idle Speed

（ rpm）2600～2650

ＰＴＯ Type Universal Joint

41.4｛56.3｝ /2400

Ｋ２５


New

181.4｛18.5｝ /1600

700 700

Silent Chain Drive/Side PTO Method

2700 2750

Engine Main Parts

Cylinder Heads & Valve Mechanism

Cylinder Head

Cylinder head is common with K15, k21and K25

Made of aluminum alloy material

Rocker Cover

Removal of rocker cover and gasket:1. Remove the rocker cover retaining nuts.2. Remove rocker cover.

Rocker Shaft Assembly

Removal of rocker shaft assembly.

1. Loosen the eight valve rocket adjusting nuts and screws to remove the valve rocker shaft.

2. Pull off the push rod.

3. When removing the valve rocker shaft, compress the coil spring slightly and tie the spring with a metal wire, as shown in the figure, before loosening the bolts. This will facilitate the reassembly work later.

Assemble Cylinder Head

Retighten the bolts in the sequence shown in the figure while the engine is cold.

Torque: 68.6 N-m (7.0kgf·m)

Assemble Rocker Shaft Assembly

Tighten the rocker shaft retaining bolts evenly from inside to outside Torque: 17.64 – 21.56 N-m (1.8 – 2.2kgf·m)

Adjusting Valve Clearance

1. Start the engine and fully warm it up. Then stop engine.

2. Remove rocker cover

3. Turn crankshaft – Set piston for No. 1 cylinder to the compression TDC and adjust valve clearance for (1) (2) (3) (5) in step 1.

4. Set piston fro No. 4 cylinder to the compression TDC and adjust valve clearance for (4) (6) (7) (8) in step 2. Adjust Valve Clearance when Engine is Hot

Adjusting Valve Clearance

Adjust Valve Clearance when Engine is Hot

Intake and Exhaust: 0.38 mm

Pistons, Crankshaft & Crankcase

PTO Device

Piston And Connecting Rod

The front of the connecting rod is determined as follow:

When installed to the piston and view from the front, the projection should come to the right.

Assembly of Piston Ring

1. Securely assemble the top ring, second ring and oil ring to their relevant positions.

2. Make sure to assemble these parts in the following order: oil ring, second ring, top ring.

Assembly of Camshaft

1. Gently put the camshaft into the camshaft hole so that the bearing bushings are no damaged.

2. Tighten locating plate to the specified torque. 8.43 – 10.8 Nm (0.86 – 1.1 kgf.m)

Assembly of Timing chain/Sprocket

Tighten camshaft bolts. Tightening torque: 39.2 – 49 Nm (4.0 – 5.0 kgf.m)


Check the height of the cam shaft gear and crankshaft gear end faces, adjust the height by adding shims to the crankshaft side as necessary.


Assemble chain tensioner.

When installing the chain tensioner, align the oil holes of the tensioner body to those of the cylinder block to ensure that the tensioner spindle shoe (synthetic rubber) is held parallel with the chain.

CAUTION: Assemble shoe correctly

Installation of Crankshaft Pulley

Set the crankshaft pulley by aligning the pulley claws to the groove of the bushing.

Inlet and Exhaust System

Inlet and Exhaust

Cooling System

Coolant Block Diagram

Water Pump, Fan & Thermostat

Engine Coolant Sensor & Transmitter

Remove Water Pump

1. Open the drain of the radiator and extract coolant.

2. Remove the radiator shroud.

3. Loosen the alternator adjusting bolt.

4. Fully put aside the alternator toward the engine.

5. Remove fan and fan pulley

6. Remove water pump together with the gasket.

Water Pump Inspection

Check the water pump vanes for rust and pitching.

Do not disassemble water pump

Water Pump Inspection

Check the water pump bearing for proper end play and smooth operation.

Do not disassemble water pump

Fan Belt Tension

Belt Deflection: 11 – 13 mm

Force: 98 N (10 kgf)

Fuel System

Fuel System Diagram

Fuel Pump & Fuel Filter

Periodically inspect, clean and replace fuel filter.

Clean fuel filter every 3 months.

Vacuum Piping Diagram

Carburetor and Governor

Carburetor Assembly

Spark Plug Gap

Standard (mm) : 9

Lubrication System

Engine oil Lubricating system

Engine oil Lubricating Flowchart

Oil Filter

Oil Pump

No service parts. Replace drive shaft assembly or oil pump assembly

Oil PressureAt idle, 98 kPa (1.0 kgf/cm2)At 2000 rpm, 274-313 kPa (2.8-3.2 kgf/cm2)

Engine Inspection & Adjustment

Engine Speed Measurement

1. Remove the distribution connector from the coupling as shown.

Engine Speed Measurement

2. Connect the ignition coil adapter harness between the distributor connector and coupling. Connect the tachometer power supply terminal (red) to the battery positive terminal and the black terminal to the battery negative terminal. Connect the measurement terminal (green) to the measurement wire in the middle of the adapter harness

Engine Speed Adjustment

1. Start and warm up engine sufficiently.

2. Check that FICD (fast idle control device) does not contact the carburetor throttle lever.

3. Adjust the idle speed by using the throttle adjusting screw and idling adjusting screw. Idle speed :700 ± 50 rpm

Caution: The idling and maximum speed are preset at factory. Do not adjust unless necessary.


4. Adjust the ignition timing for idling.


Ignition timing: BTDC:

K15 : 0o

K21 : 2o

K25 : 0o


6. Remove the vacuum piping from FICD and plug the pipe openings to prevent air leakage.

7. In this state, the FICD pushrod is pushing the carburetor throttle lever. Adjust engine speed to 1200 – 1500 rpm with the throttle lever adjusting screw.

8. After adjustment, connect the vacuum piping and verify that an appropriate engine idle speed is obtained.


Governor Adjustment (No Load)

Caution: The governor is preset at factory. Do not adjust unless necessary.

1. Set the directional lever to neutral position.

2. Start engine and fully open the throttle. Monitor the engine speed.

Maximum speed with no load

K15 : 3,600 rpm

K21 : 3,600 rpm

K25 : 3,600 rpm

3. If the engine speed does not fall in the specified range, adjust by turning the governor adjusting handle.

Governor Adjustment (With Load)

Caution: The governor is preset at factory. Do not adjust unless necessary.

1. Set the directional lever to neutral position.

2. Start engine and fully tilt the mast rearward with the tile lever.

3. Fully open the throttle and monitor the engine speed.Maximum speed with load

K15 : 3,000 rpm

K21 : 3,000 rpm

K25 : 3,000 rpm4. If the engine speed does not fall in the specified range, adjust by turning the governor adjusting handle. In addition, adjust the maximum engine speed with no load.

Testing Compression Pressure

Unit: MPa (kgf/cm2)

1. Warn up engine and then stop.2. Remove the spark plug.3. Connect compression gauge correctly to the cylinder plug hole to be measure.4. Set throttle valve to the fully open position. Depress the throttle pedal to the fully open-open position.5. Crank the engine and read gauge.

K15 1.27 (13.0), 250 rpm

K21 1.23 (12.5), 250 rpm

K25 1.27 (13.0), 250 rpm

Note: Keep engine speed at approx. 250 rpm Take reading in a short time as possible

Maintenance Schedule

Maintenance Schedule

Documents

K15/21/25 Gasoline Engine Service Manual # 99789-75100