I have a Raptor that runs great, however going down hill against compression it pops
it is stock, with the exception of a Yoshi slip on?
Any thoughts?
Thanks in advance
D

 

I got no idea, but my warrior does the same thing. I think it might be something with the carb jetting.

 

I get the same problem too if the hill is steep enuf or if i slow down really fast with the gears. I think its to do with the momentum and angle going down the hill. More fuel will flow into the engine making it slightly more rich giving it the backfire etc...