anyone got any ideas before i go completely bald,i have a 1986 yamaha 125 DT with 4500 true miles which i tried to use during the winter to save my decent bike, the problem i have is when it runs it is ok,but at other times it will start with the first kick but when i twist the throttle it stays at tickover speed and will not rev up. I have cleaned the tank and fuel lines,stripped the carb replaced the float + needle,main jet. Is it a engine or electrical prob any help would keep my barber in business thanks.