Motor ran great last year. Parked it with Sta-bil as always. This year motor starts and idles fine but will not power past 3600-4000 rpm. I realy think it is fuel related but not sure if there is an easier way (ie. some sort of additive) of resolving the problem without draining the tank. Access is not good. Any help would be greatly apprieciated. Also, any good links for parts would be helpful. No yaha dealers within 70 miles of me.