I'm running the idle mixture screw 1/4 turn in from where it is so rich the engine slows...turn slowly counterclockwise until the engine runs great, then runs slower, then turn the screw back in a 1/4 turn from the last point it ran the best.

I have about 1.5mm of spacers on the needle.

I'm using a 150 main jet.

I have the stock intake & exhaust.  I don't think the K&N air filter element makes any difference except possibly when very clean at 100% throttle and high rpms, so the 150 main should cover that...if not, try one size bigger, but give the 150 a try.  No intake gizmo makes any difference when the throttle is doing its job when part open--ya gott'a be wide open and high rpms to max-out the air flow in the intake.  I'm not a K&N fan anyway; I think they pass more dirt than a stock filter and pass much less air when dirty than stock with an equal amount of dirt.

I'm running no spacer, 152.5 main, 55 pilot with bleed holes and 3/4" turn out on the mixture screw.  I'm at 900ft elevation with yearly average humdity of 63% although monthly average humidity this time of year is around 78%.  I was using the 155 main but went back to the 152.5 main.

jake d wrote on 04/22/09 at 16:21:19:


It's a quasi velocity stack intake that is composed of a K&N filter on the end of the stock tube with an internal honeycomb screen designed to the specs of the screens used in wind tunnels to decrease air turbulence/increase air velocity.