08 yz450 popping

[Yamahajoe292]

I'm having troubles out of it popping on decel a lot more than it should, and it does it some on accel before it gets warmed up, I have checked for air and exhaust leaks and can't find anything. Could this be something in the jetting? Also it has the stock air/fuel screw and was wondering if a aftermarket one from a 08 crf450 would work?

[Treeyz450]

I'm having troubles out of it popping on decel a lot more than it should, and it does it some on accel before it gets warmed up, I have checked for air and exhaust leaks and can't find anything. Could this be something in the jetting? Also it has the stock air/fuel screw and was wondering if a aftermarket one from a 08 crf450 would work?

It sounds like it is lean to me. Have you changed anything to make it lean?

Usually I will have to adjust my fuel screw on my 08 when it gets really hot or cold just for better throttle response. Richer when it's cold and leaner when it's hot...........

[colerlone]

Mine always popped on decel, especially when it was cold and or cold outside. I read it was that muffler. N to get it to stop u had to run it so rich you would get othwr problems

[grayracer513]

Decel pop is normally either an air leak into the exhaust at either end of the header, or a lean idle circuit, or both.  If you have an exhaust leak, making the idle richer isn't going to fix anything.  Once you have the pipe sealed, then adjust the fuel mix according to the manual, and if it pops a bit after that, it's just normal.