Not sure what is happening. On a flat road with no wind, my TW tops out at 55 mph. I am running 15/50 sprockets and weigh 175 lbs. At 8000 ft with stock jetting and fuel screw out 2 turns. Bike feels great up to 45 mph. I live in a small town and don't see speeds much more than that. My plug looks like it could be lean or rich and i'm not sure how to tell. I was running a pod filter but just got the parts and got my air box back together and reinstalled on the bike. Any suggestions would be great.