I'm trying to fix a neighbor kids bike. Looking for some help please. The bike starts, doesn't have to be choked when cold at about 70 degrees outside. When the bike starts, it revs high and won't idle down. The throttle cable is working fine. The throttle slide and needle are not hanging. I've had the carb off and the jets are clean. What's odd is that when you choke it, the r's don't change. They remain high, almost to the point of over-reving. The jets are clean, the bike is stock and was running fine, then all of a sudden the boy said he went to start it and it was over-reving. When I back out the idle air mixture screw, the r's drop, but it runs real rough. Acts almost like its getting too much fuel? It's a 2003 model, the boy got it for Christmas last year, and doesn't have the money to spend getting it fixed right now. I'd really like to help him get it fixed. Any advice would be greatly appreciated.