Who knows how to jet a Raptor 660R for a K&N with no airlid and full Big Gun Exhaust?
I am at about 5200 feet elevation. Thx for the info

 

Hmmmm........Top end: Try 160-165 or 165-170 Mikuni mains(maybe larger if head work done) as long as it doesn't bog on top. If it reaches peak power before full throttle, then its a lean on top. If it takes too long to reach full throttle, then its rich on top. Too rich mains also causes a little bog or stumble on hill climbs & major elevation changes. In other words, she seems to run perfect on flat trails but acts up on the hills, then jet down one size on the mains.

Mid range: Stock needles. Clips=3 each in summer & 4 each in winter. When slowly reving it thru the midrange, if it seems to hesitate & then really take off when you open the throttle, then its lean in the midrange, try a lower clip position.

Low end: Fuel screws 3 each in summer & 3.25 - 3.5 each in winter. Pilot jets = 25 each. Stock 22.5 pilot jets will work fine, just use more turns each side. When you rev it & release it, if it takes a while for the revs to drop down to idle, then its lean on the bottom end. If it drops below idle rpm after you release it, & then climbs up to idle rpm, then its too rich on the bottom end.

Have fun, experiment!

 

For 5200 feet that will be a bit rich. I run at that altitude normally and with full Yoshi and K&N with holes in airbox lid I use 150-155. I just changed to 155-160 for an upcoming trip to Dumont and that's pretty rich at my home altitude of 3600'.

 

He is running without a lid which is much leaner than a few holes in the lid.