I have just finished rebuilding my 87 250x motor. it is .020 over witha wiseco 12:1 and a brand new stock cam, with all new valves, I put on an fmf megamax 2 full exhaust and i have drilled holes in the air box, and there is a uni filter inside, what can you guys recomend for jetting with this settup?

 

Your setup is like almost identical as mine. I bought my 87 250X off of a ole buddy. Well rode it for two hours and it locked down. Put it in the shop, had the top end completely rebuilt and bored .30 over and a new wiesco piston. Got it back and the counter shaft stripped out, so then i rebuilt the whole bottom end. Got it back and now i cant get my stupid jets right. I dont think there is a set jet for them. Its called Tinkering and Tinkering until you find the right size. i think i got a 150 in mine but it still isnt right. Its kind of disgusting tho, casue this bike is in tip top shape. Been stripped down, frame redone and dipped, new dura blue axle, new douglas rims and tires, AC skid plates all underneath, front bumper, DG rear bumper and nerf bars. I mean my ole girl is a-arms and works shocks away from being FULL race ready. I just cant get the carb. jetted right.