Have youchecked charging system to see if its charging? voltage reg/recf.? also if check out okay, than run atv without fuel cap tank may not be venting!!!Also when atv quits running check spark at plug right than and also pull fuel line off tank or carb. right than to see if fuel is running out of tank, this is the best test I know of..

 

Its charging 13.6 when it does run and I checked the spark and to me it looks erratic. Not steady. I wondering if its the stator or pick up coil. As soon as it sits 10-15 minutes even with the fuel shut off it will fire right back up.

 

Did did you ever figure out what was causing this mine is doing the exact same thing will run for only about a minute or so then pop and die