I got a 2001 YZ426 and I am trying to fix a problem with my jetting I think. My bike runs great, starts find, but is running rich from what the plug looks like. It hesitates a lot from no throttle to 1/4 throttle. After that, all is good. I have dropped the needle on clip and leaned out the pilot let 2x. Which it is now a 38 pilot, 160 main, white brothers e-series pipe with stock head pipe..I am now thinking of leaning out the leak jet...Its a coincidence that I just removed my flywheel weight and rekluse clutch and my muffler broke and now I have jetting problems..I Had the muffler welded and repaired, but when reinstalling it. The exhaust gasket from the pipe to the headpipe fell apart. I put it together the best I could and probably going to buy a new one. Does anyone know if that exhaust gasket could make my bike run rich? Am I doing the right thing? ANyone please help, I am frustrated and have been tweaking my carb for the past 3 weeks... One more thing, the intake boot going into the cylinder is tight but I can still twist the carb fairly easy..Will that affect jetting? Is it normal..