06 YZ450F decel popping

I have ridden my 06 YZ450F 5 times or so and the first 4 times it ran great. Then the last time I went riding, it popped badly on deceleration. I have a WB carbon pro 2, quickshot, and an aftermarket fuel mixture screw on it. the temperature was cooler the last time, but i didn't think that would have that much to do with the decel popping. i did adjust my fuel mixture screw, but that didn't seem to have too much of an effect. wondering if anyone has any thoughts??? any advice would be greatly appreciated. i live in WI...

You might need to rejet your bike. I had the same issue and I went with the JD Jetting Kit. I am running the 170 main jet and the 48 Pilot Jet as advised by many on this forum. It really helped the popping on decel.


I'm running 168/48 and have no issues w/ jetting at all. Starts easy (even in gear), no popping, bogging or backfire either. :excuseme:

What pilot jet are you running? have you been running U4 or any other race fuel? you may have something partially blocking your pilot circuit or jet. If you don't drain your float bowl after each ride day, especially when running race fuel it will corrode your pilot jet and could cause what you're experiencing.

install a 48 pilot and adjust the fuel screw as needed

Yep, cooler weather does make a difference, there's more oxygen available. Try the #48 pilot.

thank you all for the advice, i will try re-jetting and see what happens!!!

you might try cleaning the hot start plunger,sometimes they stick open a little and that will cause poor performance....backfiring when off the gas especially

You may want to hold off on the 48 pilot and go to a 45 instead. The '06 came out in the late fall, and most guys were first setting them up in the winter months. Some of those who jumped on that bandwagon are backing down now that warmer weather is coming.

Read back up from this post a ways, and you can follow that thought as it develops:


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