YFZ 450 ignition missing at High rev

[Rick_YZ]

Need Help! My 450 is missing at high rev. Already tried new plug, new coil, rev box. Running full GYTR pipe, K&N, air box lid off. Jetting at 45 pilot, down one needle size on clip 5, 165 main, 1 1/2 out on air screw. Any sugestions? Is there a chance the timing is off?

[LTandRaptorider]

Originally posted by Rick_YZ
Need Help! My 450 is missing at high rev. Already tried new plug, new coil, rev box. Running full GYTR pipe, K&N, air box lid off. Jetting at 45 pilot, down one needle size on clip 5, 165 main, 1 1/2 out on air screw. Any sugestions? Is there a chance the timing is off?

sounds like it's starving for fuel in the main jet circuit. try 2 sizes larger on the main, see how it revs out. you could try putting your air box lid back on for a quick check.

[SRH]

put your headlights on and put them on on and ride it , see if it helps