my friend has an 02 Raptor he brought used and it has had a starting problem since day one . if i pull start it with another quad it starts up fine. it takes a minute to warm up thought and also he has to turn the ilde up a litle to keep it running. he just put a pistion ,cam and bored it out some. it fouls plugs in like two days also and back fires ( think that means running lean ). the only things he has on it is exhuast and k@n filter. he know it needs jettign but could anyone please help with any of these questions thanks
Alex

 

If he is fouling plugs he is probably too rich or since he recently bored it, there is always the possiblity of a ring or bore problem letting oil to the top end. Do the plugs look oily or are they just carboned?

~HoundDog

 

the last plugged he changed only had a little carbon on it. would that still affect the starting poblem . it will crank the first few tries then just go to dead nothing.

 

If it backfires it's too lean. He better call someone that is familiar with the bore and get some specs on jets.

 

Sounds like you have more problems than you think. First I would get a new battery and do what KingoftheRaptor mentioned.