08 Yz450 Exhaust popping and backfiring

Hi everyone, im new to this forum and its a really informative place. My question is about the popping and backfiring on my exhaust on my 08 yz450. I have a Yoshimura pipe, im thinking the jetting maybe?Thanks in advance for any info..

Hi everyone, im new to this forum and its a really informative place. My question is about the popping and backfiring on my exhaust on my 08 yz450. I have a Yoshimura pipe, im thinking the jetting maybe?Thanks in advance for any info..

Set the mix screw at 2 to 2 1/2 turns out, it will have some popping no matter what. I have an 08 with the full FMF exhaust, so I've been down this road.

If you have stock pilot jet, that could also be the reason. Install larger one (maybe 2 sizes larger, forgot the # though)

Other than that, if your header is not sealed well at the motor or at the header/mid pipe joint that could also cause popping.

I had a 08 yz450 with a dr.d pipe and I just upped the main jet to I believe a 180 and the bike ran awsome. I had a quick adjust fuel mixture screw for minor tweaks. Also keep the air filter really clean on that thing and it will never let you down. I had 130 hours on mine when I sold it and i never did a top end of shimed the valves, but those motors seem to be bullet proof

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