Just bought a '06450 and I notice at higher RPM's it will pop or basically sounds like your clapping your hands together, not everytime the piston comes around but often enough to worry me. Keeps accelerating, but I'm thinking it's running out of fuel? My guess is I need to richen the top end up slightly but I was also told to leave the jetting and get a fuel screw and it will usually solve the problems if any. Bottom end is PERFECT no hesitation or any studdering what so ever. Just the top end issues mentioned. FMF factory4.1 slip on, boyesen quick shot. Not sure if the previous owner changed the jetting at all. Calling him tomorrow to ask and I'll post up then to give the tuning GURU's some more to go off of. One more note: Would a loose wire in the stator or any of the wires exiting the stator cause anything? Asking because it looks almost jimmy rigged where the wires leave the stator, and one of the plugs on the cover looks like it was removed unproffessionally (little chewed on). just trying to cover everything, sorry for the novel.