Ten secrets for getting good mileage:
Always service ur bike at correct intervals from an experienced authorised servicing centre and make sure all the periodic servicing works that are mentioned in the owner’s manual are done correctly during servicing. Keep the carburettor settings as per the factory settings. Never alter these settings. If ever altered before, then ask an experience authorised service man to bring to the original settings.
Always maintain ur bikes engine rpm below 4500. 3500-4500rpm is the most economical rpm range for riding a bike.
Most important is that u have to close the fuel tap when u r parking the bike under the sun or in open places. Every time u forget to close it, u will loose the fuel through evaporation, which is enough for riding 1-2kms. It may appear as a very small figure. But when u do this mistake 5 times, u will loose 5-10kmpl in mileage and people will find fault with the innocent bike.
Use clutch only for changing gears and while the bike is gonna stop. Never ride with half clutch. Always use the correct gears according to the speed of the vehicle for driving. Always ride in the highest gear possible while riding the bike. If u r able to ride ur bike at 40kmph in fifth gear smoothly without any engine stalling or knocking for a long period of time, then do it. Never lend your ears to others who may tell u that u can use 5th gear only after crossing 60kmph. Also never change gears very frequently. So plan ur driving accordingly.
Always maintain correct tyre pressure. Check the tyre pressure atleast once in two weeks if u r using the bike frequently and once in one week if u r using the bike rarely.
Maintain correct tension of brakes, clutch, drive chain and accelerator. Never over tighten these. Maintain correct freeplay.
Maintain a correct engine idle speed of 1500rpm. If its more than this, then get it reduced.
Always keep ur bike in good condition. Change the worn out or damaged parts like tyres, chain sprocket, clutch discs, silencer etc immediately. In case of decrease in mileage, check whether there is any fuel leakage from petrol tank, fuel pipe, fuel tap or carburettor. If yes, then replace the faulty part.
Always accelerate the bike gradually. Never give the bike a sudden or rapid acceleration.
Always stop ur bike gradually only. Never do sudden braking unless in case of an emergency. First decide where u r gonna stop the bike, then from about 50meters before that point, u have to release the accelerator and slow down the bike by changing gears down and applying the brakes gradually. This is the correct method of stopping a bike and will increase mileage also.
If these rules are followed correctly, then a 150 cc bike will give 50kmpl mileage normally. But in case of driving in extremely heavy traffic condition, the mileage may lower to 45kmpl and even to 40kmpl in case of some 150cc bikes. Nothing can be done abt that. You have to bear it.
U can increase the mileage by tuning the carburettor and making the fuel/air ratio of the fuel air mixture low. In this case the mileage will increase by around 5kmpl. But after doing this there wont be any fun in riding the bike. U will feel like u r riding an underpowered bike and there will engine knocking. The engine will starve for fuel and this will decrease its life. So I wont recommend doing this.