450r back fire problem

[SlowJoeRacing]

Has any one heard of there bike back fireing going over a woop section. I am thinking it is hitting the rev limiter too much but not sure. If you can help me it would be great

[TRX450R_Racer]

Back fire and rev limiter are 2 different sounds. Which one was it?

[SlowJoeRacing]

my dad is thinking that i am hitting the rev limiter too much and it is just back fireing

[Mike99KFX]

Do you have an aftermarket pipe on it?  I chased a backfiring problem for months on a YFZ.  Everyone said it was jetting.  It ended up being a leaky Big Gun headpipe.

[SlowJoeRacing]

i have a stock pipe but i have an hrc kit in it. When  we where at croom we asked jeff pickens if his did it. he thought it might be the hrc kit and for us to change the jet. when we changed the jet it still back fired.