Hey Team...need help with a recent purchased '06 450 Sportsman. It starts easily but need to be above 1700 RPM to stay running...and there is a real bad backfire when you de-accelerate. If I leave the choke out just a bit, it stops. I have completely changed the fuel, added a gas treatment for carb/valve cleaning, checked the ect adjustment to make sure the contact points are not touching during steering/operation...has me completely stumped. It has 300 miles on it and wondering if the valves need adjusted???? Please advise this newbee....Thanks.

 

Okay so I have a 2000 smc ram 250cc quad I baught off my uncle it won't start due to carb mixture screws and idle screws being tampered with by someone when my uncle had it I'm having trouble setting them so the quad will run sometimes it fires up then dies almost instantly this quad has 2 carbs I know they have to be in sync with each other but I don't know the correct amount of turns on each mixture and idle screws to get it going can anyone help me with this if I screw both mixture screws in fully how much do I screw them back out also with the idle screws if I screw all way in how many turns out should I do