I bought this last week used, it was not running. I cleaned out the card and gas tank and added new gas and it fired right up and ran great for a week then my son took it out with his buddy and it died on him after about 20 minutes of riding. After he brought it home I started it up and rode about for 2 minutes. It was running fine then it died. When I try to start it, it just backfires really bad. If I let it sit for a while it will start right back up and run great for about 1 minute then dies again and will not start it just backfires. I have done the following

1) made sure I have a good tank of gas and the carb clean
(2) install a new plug, properly gapped
(3) bump up the idle with the idle speed adjustment on the carb
(4) checked to make sure I have a clean air filter.
(5) checked the carb bowl after it dies and to make sure there is gas in the bowl.

the bike is stock

Any help would be greatly appreciated

 

Unhook the reverse overide switch(disconnect) and see what happens.
Hand a Polaris 500 and that fixed the problem. Good Luck.

 

Well I never thought that would work, but after messing with everything else on the bike I finally disconnected the bypass switch and it runs great

Thank a lot for the help

barryc