carb tuning 2k-6k rpm

Ernest Montague afm199 at
Sat Sep 5 22:50:47 PDT 2009

stock pipe? stock airbox? emissions gear removed or on the bike?

One step up on pilots is 17.5.  If you are 3 turns and 17.5 jets I'd be 
looking for an air leak somewhere.

I'd turn in the screws to  2.5 and see what happens. One thing at a 

On Sep 5, 2009, at 10:06 PM, matthew patton wrote:

> I have minor backfiring at idle and closed throttle. it used to be a 
> LOT worse but I richened up the idle circuit to 3 turns on 1 step 
> richer needle jets (15's??), and it's decreased noticibly. but I'm 
> rich (f/a of 11.7 at 3200rpm to 12.09 at 5900rpm) after which at 6000 
> rpm I hit 12.2 (theoretically max power) and make a slow rise to 13.5 
> at 8000 rpm and then a slow decline to 12.8 at 10,000 rpm.
> so mains seem to be decent. it's the early circuit that's off. i'm 
> thinking of 1/4 turn in on idle mixture and 1/2 notch lower on the 
> needle (factory pro 10 kit). that sound about right?

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