I bought a new 01 426 about 2 months ago, just as everyone else I began fouling plugs after break in. I spoke to a friend of mine who also bought one because he owns his own shop and he said his was doing the same thing. My bike even with a new plug would run like crap, and this is not my first 426 so I know how it should run. Anyway, my friend spoke to someone that he said is a Yamaha Technician, the guy told him to disconnect the light blue wire out of the cdi, he said it goes to the neutral switch and is causing low voltage output out of the cdi. I thought it sounded like a bunch of crap but I tried it, without any jetting changes and It ran like a dream today. I rode about 40 or 50 miles and it ripped. I had no problems starting it hot or cold, didnt even have to use the hotstart. I know it sounds too good to be true but its worth a try and its free. Let me know if you have any luck, so far Im extremely happy. Norman K.