[JGH400x]

hello people new to the site, I have a 2009 400x i bought brand new and last year i installed a big gun full exhaust and K&N air filter i also bought a dyno jet kit and installed the required jets but after that it wasnt running that good so i took the jets out and put stock jets back in, and this was last year ive been riding it alot and i just dont want to damage the atv from not having aftermarket jets. if anyone knows what jets would be good or any advice would be much appreciated. thanks

 

[tomgodd]

I use the factory style hex jets. Dyno jets differ from them in numbers and sizes. It's a test and tune situation. Call Dyno jet and they can give u a rough guess on what jets to start with.

 

[tomgodd]

TThe stock jets are to lean in most with stock parts. there is a link in my signature. it is a sister forum to this one. some smart guys there that can also help.

 

[JGH400x]

thanks for the replys