My wr450 2004 backfires and I need to know what to do to stop it.
sounds lean, I would try richening your mixture a little.
SINCE i made mine run richer its has never backfired. I went up on the main and pilot. i think im running a 170 main and a 150 pilot( i dont remember????) but i also have a white brother exhaust and holes drilled in my air filter cover for more air and im below sea level. Runs great!!!
Richen the main jet by to a 168 or 170 depending on altitude and turn the mixture out to 2 1/2 to 3 turns. Get a JD needle kit. They better than stock. Also use a mixture of race gas (110+-) and premium (91+-) to get a 95-96 octane. Your problems should go away.
You need to be a member in order to leave a comment
Sign up for a new account in our community. It's easy!
Already have an account? Sign in here.