I have a 2001 Yamaha GP800R and it has great top end but when i gas it sounds as if its about to stall. It just grumbles and doesn't move anywhere but if i feather it i can get it to 15 mph then it will take off. I don't know if its a carb issue but i was reading a thread and they talked about a wear ring that was bad and they get no low end but it sounds as if the engine doesn't give of power in the low end.