I have a 2005 blaster with full fmf exhaust, k&n air filter and I'm running a 220 jet. I've been running this same setup for about two years now with no problems. It stumples and cuts out at full throttle with the air lid on but if I take it off it runs like new again. I have cleaned carb, and anything that flows air through it hoping to find a clog but nothing. This problem started the last time I rode I got a flat and had it limp it home. I tried jetting down to a 215, 210, and a 200 with lid on but same results. Any info would be appreciated.