My son has one of the 110cc Chinese atvs that alot of people bought for their kids this past chritmas. It will run fine for 20-25 minutes after it has set up for a couple of hours. It has gas and spark. The only way to get it to start after it has died is to wait. Anyone have any suggestions??  

do a valve adjustment, 80% chance you have tight valves  

when's the last time you adjusted the valves? never? start with a valve adjustment , set both valves at .004