Hi, I have a 2001 Yamaha warrior 350. I recently have been trying to get it riding again but whenever I try and start it, it full throttles and I immediately hit the kill switch. I have looked at the carburetor to try and see what the problem could be and the butterfly (I think its called) isn't closed all the way to where it should be it is about halfway open and it wont close. Also the quad will not start up unless the choke is on. Before the quad was having the throttle issue I would try and let the quad idle so the engine would warm up and then I could turn the choke off but nothing seems to be working. If u know the problem or could help me at all that would be amazing.

 

Is the throttle cable keeping the butterfly open? If so check the thumb lever isn't seized on the handlebars. If it is the cable itself seized, get a new cable. If the cable is not keeping the butterfly open, the shaft is seizing in the casting. You have to remove the butterfly, then remove the shaft, clean and lubricate both, make sure the shaft is free and re assemble, making sure those screws are not going to come out and get into the engine. Many are riveted in, so bad to get out. Unless you are used to fine work, fitting a new carb may be a better choice.