86 250R JETTING ?'s

[wanta86r]

I am putting a new .20 piston in my 86r. i also am adding a esr pipe and silencer, ftz reed valve with carbon fiber reeds, and a keihin pj 36mm carb(supposedly bored to a 37.)I paln to run it with the lid removed. I dont have very much knowledge of the carb and have no idea where to begin with the jetting/ needle etc. anyone with any suggestions please help

[Red Rider]

I used to run a similar setup at sea level & 70 degrees OAT. I would recommend starting in the 160-165 range for the main jet & with the needle clip in the middle position. I'd also put a few hours on that new piston before doing any plug chops. Just ride it around leisurely a little bit & check the plug to be sure you're not running too lean. After you've broken in the piston, I'd start doing some plug chops at various throttle settings to fine tune the carburetion. Good luck.