Bought atv used. Replaced the full auto clutch unit. Why does it need almost 3/4 throttle before it will start to move. Once it does it goes just fine. Slow speeds it really puts a strain on the motor to give enough power to just sustain. It wants at least 3/4 throttle or none at all. Any help is appreciated. Never owned a full auto before.

 

Sorry to be rather slow to reply, but thought someone with experience of this engine would have done so. The GY6 engine has a belt drive variator and you must have a problem with it, probably pulleys stuck. Take a look at the on-line videos of how variators work and then dismantle the one in your belt box. A fairly simple thing, so cleaned up and pulley sheaves checked that they slide OK, you should be good to go. Rear pulley is spring loaded so don't take apart unless it's sheaves are sticking. Belts can go an odd shape if left standing for a while, if your belt is like that, either fit a new one, or you will have to put up with a "lumpy" take off for a while.

 

Thank you for the info. I will be looking into the variator that you mentioned. Will update soon.