450 king quad back fire

[mpriverat]

coming down a hill ,my new 450 king quad back fired several times. (very loud) Took it to the dealer, he found no problems. Any others have this problem? Ideas?

I put a foam air filter in, and made sure it wasn't running hot..

[400eXr1d3rZ]

Is it an semi-automatic? If it was an you were coming down the hill in a gear and the rpms were kind of high but bouncy, it's normal.