need help

[m_noel79]

I have a 2001 400ex with a 440 over bore kit in it k&n jets and filter stock air box and a rev kit . My quad was running right at first but then i went on a long ride and it started runnig poorly at mid range and top rpms any ideas, maybe jets or timming?

[firefighterjosh]

I would guess it is running lean and got hot. What jet size you running?

[m_noel79]

Ya it got really hot that day , I'm runnig a 165 main jet and the top notch on the needle I never toched the pilot

[m_noel79]

is there any other ideas out there for me

[swva400ex]

whats your elevation

[Mx_523]

Was it bogging out? Does it smoke? Were you giving it hell? Since its cooled down try it and see if it still does this. Check to see what color the spark plug is also.

[krt400ex]

Originally posted by m_noel79
Ya it got really hot that day , I'm runnig a 165 main jet and the top notch on the needle I never toched the pilot


i would go with a 170 Keihin