It is backfiring when it hits the rev limiter in the air (i have to pull the rear end down quick to land, so i smash the throttle). Also it is missfiring alot. I need to know what causes backfiring and misfiring.

A while ago when i removed my headpipes to install my 3 quart pingry, i never replaced the copper crush gaskets, could this be the problem?

plz help

 

the gaskets are not the problem. I don't know but I would start with the simple stuff first. Maybe a new spark plug, jetting, or try to see if anything is blocking the exaust flow.

 

What i meant by the gaskets was that maybe a leak there caused a hole to wear in the piston, causing backfires and misfires

 

Did you develop the misfiring problem only after having the exhaust off and back on? Has this ever occured before?

 

yeah, it misfires ever since i took the headpipes off... i had to take them off again to align up the white bros slip on too...

 

jet a little lower maybe i had the same problem w/ my wb pipe. i thought i was jetted to lean and the backfiring only got worse so i jetted a little leaner and ran fine