complicated 330ex question

[Sparky416ex]

I just had my 300 motor built and im trying to jet it. I did a 330 kit, a high compression piston, port and polish, 254 MX web cam,and a rev box mod. my engine builder (profab atv) is telling me that the bike will run great with a stock 400ex carb with a slow(pilot) jet and a 148 main jet. stock 400ex jetting is a 148 main with a 38 slow jet(pilot)...my dad is going to give me his 400ex stock carb, which has a dyno jet kit with a 38 slow (pilot) jet, my question is...id like to keep the dyno jet kit, but the dyno's are measured differently which dyno jet would be closest to a stock 400ex 148 main jet?:eek2:


thank you

[Mr_Bub400ex]

some one should make a guide for the new tech articles about this... sorry i couldnt help:ermm:

[Castor-426ex]

whats the smallest main in your dyno kit?

[Sparky416ex]

Originally posted by Castor-426ex
whats the smallest main in your dyno kit?

ive got them all...tonight we went back to the stock 400 jettin...because scott at porfab said to....we are still having some popping porblems when we let off the gas...but otherwise it runs like a raped ape

[Castor-426ex]

what kind of problems? popping?