Hello. I have an 05 Sportsman 400 AWD. Since it started getting cooler up north here, which isnt even that cold yet(30 degrees F), It has not wanted to idle. Runs great while driving. Will not idle. Seems even if the engine is warmed up, still wont stay running. It has to be running for almost half an hour before i can get it to stay idling. Once it does stay idling, if i turn the handle bars, it will kill the engine. The only thing I have checked was the air filter, and I have changed fuel. I am new to ATVs in general so any help would be greatly appreciated.

 

Welcome! Make sure you have only 1/16" to 1/8" slack at the thumb throttle. A lot of play will cause the etc internal switch contacts to touch and the machine will die when you release the throttle.The adjuster is under a rubber sleeve down from the throttle housing. Make sure this is adjusted correctly first along with checking for any throttle cable binding. Then you should be able to adjust the idle at the carb adjuster to 1100-1150 rpms.Also make sure you just have the key in the ignition and NO key chain as it can barely turn the switch when you turn the bars and kill the machine. OPT

 

also, you might want to check out the carburetor and the idle cable. we had the same problem with ours and took it to get it serviced and checked out, and the guy at the shop said that when then carb got rebuilt by the last owner they didnt put it back together properly which was causing it not to idle at all. the total cost of parts and labor was about $270.