Getting The BasicsI am assuming that you know driving very well and have completed at least 1000kms on road. If not, then you are too amateur to read this guide.Every bike has a engine (motor/mill/muscle) and a carburetor (breathing system/heart) Yeah I know that. My point is, I assume that your engine is in perfect condition. That is, there is no oil leaking from it etc etc.. The next assumption is that your engine is not DEAD. You know where your engine is and where your carb isand you have a screw driver/blunt knife with you. Your machine must have finished at least one service ~500kms or more. Also make sure you do not change the fuel type while tuning i.e. Power, Speed, Extra premium, normal unleaded etc.This Guide Applies ToAll the single cylinder bikes, 2 stroke or 4 stroke having a carburetor. Tachometer is very handy and amustfor a newbie or the tuning process will be very slow or painful or imperfect.Disclaimer:Though whatever I have written here wont do any damage to your machine, finally you must not blame me for whatever happens. I am here to help if anything goes wrong.So Lets Get StartedWarm the engine nicely. Go get a ride around the town. Speed nicely at least upto half the top speed of the bike. Drive at least for 10-15 minutes so the engine system warms up nicely or youll get a bad tune. Do not just leave the engine idle and start with process. I mean it. Ride the bike.Now that the engine is adequately heated up, you are ready to begin with the process. You can select a place far away from the city or your residential area so that you do not disturb the tired, sick, disgusted, old people or babes (babies) living in your colony. You are likely to be shooed away from them when you are at a critical point. You may choose a place near your girl friends house just to impress her! Put the bike in main stand and get hold of your screw driver. That is all you need, together with your eyes, brains and ears.Searching the fuel/air screw The above mentioned screws are responsible to adjust the air-fuel ratio which forms food substance for your engine. You can relate it to our human body, where proteins, carbs, fats, water etc all are required in appropriate proportions with respect to each other for good strong body.There is another screw which sets the idle speed of the machine. This screw is not related to pickup or mileage. It just sets the engine rpm at idle run. 2stroke machines have an Air screw and 4 stroke machines have a Fuel screw. I hope you note this VERY well. Air screw is located on the carb away from the engine. [ Engine - Carburettor - Air screw]Fuel screw is located on the carb but its near the engine. [Engine - Fuel screw - Carburetor]. If the make of your carb is Mikuni (Pulsar, Yamaha, Fiero) the fuel/air screw probably will be of brass (golden colour). If you fully unscrew this screw and take it on your hand, you will see a needle like tip.Idle screw is closely linked with the throttle cable. Idle screw can be turned by the hand. Screw driver is not essential for it. Finding these screws are very simple. If you still cannot find the air/fuel screw, ask your mechanic or I can help.Ok now what? Apart from the above difference I gave between Air and Fuel screw, there is one more major difference. Fuel screw turned in (clockwise) gives a lean mixture and turned out (anti-clockwise) gives a rich mixture. Air screw turned in gives a rich mixture and turned out (anti-clockwise) gives a lean mixture. Lean means more air, less fuel. Rich means more fuel, less air. This ends the basics.Getting Things In ActionTurn the idle settings screw so that rpm reaches about 3000 rpm. Now tune the air/fuel screw to make the mixture leanest as possible. Please refer to the above whether you must turn the screw clockwise or anti clockwise.As you make the mixture leaner, slowly the engine RPM decreases Go on doing this until you have put the fuel screw to the leanest possible point. At the same time, ensure that the engine does not stall, by turning the idle-screw.Tough huh? Youll get used to itOK the engine is running and the mixture is lean. If you notice from the engine sound OR if you see the tachometer, the engine RPM will not be steady at this point. Nowvery slowlystart turning the fuel screw anti-clockwise, quarter to 1/8th turn at a time. You will notice that the RPM increases slowly and steadily. Again, do this very very slowly. Also count the total number of turns as you wind out the screw.Youll notice that when you have turned it to about 3-4 full revolutions, the engine RPM slowly becomes constant. It is this point that you must stop screwing more. This probably is the optimal setting for your engine.Further on, try turning the screw even more and more to 5-7 revolutions and youll notice that the engine RPM will slowly decrease. When this happens, you are just putting in a too rich mixture in your engine. At this point the engine loses all the fuel efficiency and the mixture is not optimal. Repeat the process about 2-3 times. Count the revolutions each time and get the setting which you feel is correct.OK the engine is humming perfectly, now what? Decrease the idle setting screw to about 1000rpm in the tachometer. When the engine slows down, just twist the throttle. The response should be crisp and quick. It should not give any hiccups! Try shutting off the engine and restarting. The engine MUST start in a single kick or self with out giving throttle. If this happens, the setting is ok. Now get a ride and youll notice the difference for good or badYoull immediately notice change in the engine sound and the throttle response. Your engine can become more smooth or harsh. Another important point is, Ride and Feel. Always take a ride and get the feel of the bike in each gears, check the response and the engine sound. Youll quickly come to know once you get the feel of the bike that you want to make the mixture rich or lean.It may take a few iterations before you fix a setting as permanent. Try calculating the mileage per liter and tally it with your setting and thefeelingyou get.

How to tune the carburetor of your Royal Enfield BulletTuning Pro.=I belive ur machine is Elec-CI350cc. So that means ur machine has 3 setting screw, carb = 2 tunning screws and emission controlling unit = auxy screw which is known as Auxilary Air Screw.

Step 1.Keep one table fan from front side for cooling the engine. (On High RPM, coz for newbie it takes some time to learn the setting, so engine might get overheat during the session, don't mind please)

Step 2.Engine should be warmed up for atleast 2 mins.

Step 3.Slightly increase the RPM so the bike will not stop.

Step 4.Close the auxilary screw which is given on the inlet manifold. Location of the screw is in between carburetor and head, one rubber pipe is connected to the same part , one end goes to resonator box(AirFilter-Chrome Plated) and another end of that pipe is connected to emission controlling kit. Equal tightening please coz we just have to close the port for some time. Do not over tight otherwise u may loose the threading portion of that alloy part.

Step 5.As u know ur carb is VM24, so the setting of Pilot screw or AF screw is in between 1 1/2 to 2 full turns.

Step 6.U should be able to feel some moisture from exhuast tail pipe.

Step 7.Decreasethe RPM by turning idling screw to lower side. Keep the idling till that point where vehicle should not stop. Due to no presence of RPM meter u can't get precise RPM number. So judgement......

Step 8.You are set with two screws till now. The next screw is Auxilary screw. Now u have to release the screw by unscrewing anti clockwise till u feel the RPM is getting HIGH. Auxilary screw increases the RPM. The point at which u will find RPM is high stop there coz if u turn it more RPM will go low. Exact point is the point where Left or Right turning will decrease the RPM. So that is the main setting point for auxy screw. Generally it comes near to 1/2 to 1 turn. depends on carb cleaning and engine overall condition.

Step 9.After setting up the auxy screw, again lower the RPM by turning Idling screw n set it near to 800 RPM.

Step 10.Checking the perfect idling

This way u are set to get good milage out of it. No lean no Rich. If u feel moisture or water droplets from exhaust tail then perfect setting. Sometimes u may feel chilled carburetor body.