06 YFZ450 jetting issues

[tsargent4]

I have an 06 yfz450, stock carb, and a FULL BUB Moto C-4 exhaust, the air box lid is off and I have a 170 main, 42 pilot, needle is stock and on 3rd clip from top as it came stock, and the A/F screw is 2 1/2 turns out.

Once the motor is at running temp. "IDLING" and the choke is off, if the throttle is blipped, it acts as if it chokes or cuts out, when riding its fine in 1st and 2nd gear, but once it gets to 3rd is kinda spits and sputters unless you punch the throttle and its fine.

Any suggestions? I know many people haven't even heard of BUB exhausts, or don't even run them, but if anyone knows what I can try it'd be appreciated.

Location: Bedford, IN (not sure of "sea level footage")

[soyo]

i would put a 48 pilot in there and the bogging your dealing with is normal. change the leak jet(little jet in the bottom of your bowl) to a 35 or 40. the smaller you go on this jet the more fuel your accelerator pump will put in the motor when the throttle is pushed. will more than likely fix your problem. keep us posted!!