help!!

[rossetti]

hey guys,
i have a 110cc thumpstar and its its runnin like a b**ch it keeps spluttering and backfiring and it doesnt seem to want fire on the power stroke sometimes ive tried turning the air/fuel screw ldie screw changed the spark plug changed the oil cleaned the carby and i was wonderin if it was the timing on the magneto and how do you time it. also i put 15w/50 oil in it i know its supposed to have 10w/40 but the shop didnt have any do you think thats wat it is
thanks.

 

[Fiddy@norway]

does it sputter on all RPMs and all throttle openings? make sure you've got the right gap on the plug also, wrong gap will make it misfire.

 

[rossetti]

yeh its usually after it warms up though. i cant even get it to idle any more

 

[Matty]

try checking your valve clearances, may be contributing to your problem... not sure what the exact clearances are but i run mine 3 thou inlet and 4 thou exaust

 

[rossetti]

it turned out to be the one of the conections on the ignition coil it was just loose and needed to be crimped a bit. theanks heaps for ya help anyways