250ex back fires

[mx8]

Bought the wife a new 250ex 2008. It back fires when letting off the gas. I think that it is more than likely lean from the factory. Just wanted to see if anyone has changed there jets and if so what did you change them to. Also I live in ohio. Thanks

[Kickstarts-suck]

Originally posted by mx8
Bought the wife a new 250ex 2008. It back fires when letting off the gas. I think that it is more than likely lean from the factory. Just wanted to see if anyone has changed there jets and if so what did you change them to. Also I live in ohio. Thanks

Whats the plug look like?

[wilkin250r]

Here is the key. Your carburetor works off throttle position only. Your carb doesn't know what gear you're in, or how fast you're going. It's all about throttle position.

Throttle closed. you're running off the idle circuit. Doesn't matter if you're sitting in your driveway, or decelerating from 50mph. Throttle closed, idle circuit. The fact that you're decelerating only exaggerates any issues because of higher RPM and faster airflow through the carb.

If you are popping on deceleration, it generally means that you're lean on your idle circuit. It could be as simple as an airscrew adjustment, or you need to actually change your pilot jet.