I got a 250ex for my 9 year old today, moving up from a 70cc full auto china quad. He also has a CRF50 china knock off, so I thought the semi auto 250ex would be the next step up. He's ok with the shifting but the quad it still a big move up from the auto 70cc or semi auto 50cc. I would like to buy one of the thumb throttles with the limiting screw on the thumb throttle. Does anyone know if I could get one from another quad and use it instead of having modifying the stock one from the 250ex?