I just bought one of the off-brand kids atv's. Its a 150cc Tomahawk. The problem is this. When you push the throttle it will not return to idle without doing it manually. Why?

 

If you just bought it I would return it for warranty work as this is a dangerous condition.Possible causes are frayed or sticky throttle cable,broken spring inside the carb,something bent or sticking inside the throttle assembly,throttle cable bent or jammed against something.The throttles are usually quite stiff on these things,don't hear of them sticking too often.

 

Stuck throttles are killers in waiting... replace the cable no matter what. I had a son dump his R1 street rocket because of it. Turns out the mechanic who had worked on it days earlier had use vice grips on the cable to pull it through the chassis and had crimped it slightly. Not a fun thing to go into a corner at speed and not be able to whoa it down.

Dealer paid for the repairs by the way... no questions asked....