Help!
I have a 1987 Honda ATC250es that bogs something awful on acceleration. I have replaced EVERTHING except the pulse generator and rectifier. New carb, CDI, good compression, valve clearance OK etc etc but still bogs. Engine is in a golf cart and I had to use an electric fuel pemp, no gravity feed, fuel pressure 2.5 PSI.
Help Please, Jack

Please respond to handyjc55@gmail.com

 

sounds like its running lean, Its possible the Carb jets may be too small, or else you may have a air leak in the intake. I had this same problem on my ATC 185s after replacing the Carb. I replaced the seal between the intake and the engine and it cleared.

First thing, did you try turning the mixture Screw out (rich)? if it goes 2 turns from all the way in and no effect, then its something else.

secondly, make sure the carburetor bolts to the intake are tight, and that the air filter is secured. if still running rough, then you may have an air leak between the Intake and the Engine. replace the intake seal.

If it still persists, time for a different main Jet in the carb. (larger jet) Kei-Hin and most Japanese Made Carbs will have Kei-Hin Jets marked with a star and a Number. Take Note of this number. If no numbers (a china made carb might not have them), then refer to the old carburetors jet sizes. try upgrading by going to a higher number jet and try it. make sure to adjust the carb when upgrading, till it runs smooth.



this guide should give you more info on carburetor jetting
http://www.3wheelerworld.com/content...Jetting-Theory