I just received my 39pwk that was pre-jetted from the factor, set up for a 250 with some mods, Does any one know how close the jetting is, and what I mean is, can I go Buy the next Four smaller main jets and the next four larger jet to dail it in?I Have all engime mods done to mine. Or is the jetting way off, and if so where should I start??

 

I ran a 39PWk in my 87 Qracer, it was ported pipe etc. I believe my main jet was a 165, I run at 5000 feet though so if I were you at your altitude I'd start with a 170 and read it from there.

 

When you get that new carb on the power is really improved. Once you get it jetted right you will have a smile on your face.