bike runs great for about 20 minutes then stalls.

[edmondson3604]

Bike starts right up, no problems there. But when I ride for about 20 minutes, it will sputter then die, and not start back up. If I let it sit for about 30 minutes it will fire right back up, but do the same stall and not start again. I am thinking along the lines of carbuerator flooding issues, or coil overheating. Thanks in advance for any help.