Im in eastern north carolina less than 1000 feet. Bike ran fine before adding pipe and silencer. Had ap mod done, wertzy fuel pump cover. ran 45 pilot 138 main clip 3rd fuel screw about 2 turns. Never did change leak jet. Bike ran fine no problems, no bog. The we Added exhaust. Idle erratic idles high then dives low Plug looked lean. moved pilot to 48 main 140 Ran much better but idle still crazy. Good increase in power compared to stock pipe. Ran it that way for last two weeks. All of a sudden started breaking up really bad mid and high. No power when riding. We were at the races so all i could find was a 138 main. Dropped it and there was some improvement barely good enough to ride, kind of dead out of a corner still breaks up mid and high. If it was a two stroke Id say it was rich but at this point Im confused. Can't follow your directions for pilot circuit setting cause bike won't idle properly to do so. Tryed looking on FMF website for jetting specs for pipe when I first had trouble couldn't find any. Can you help me? I think the weather has been roughly the same for the last three weeks. If I was running a two stroke there would have been no reason to be rejetting.