It starts fine, but once it warms up it idles extremely fast?

It starts fine, but once it warms up it idles extremely fast. Then it starts to shake and eventually coughs out. It will only restart if you hold the throttle all the way in and even then it coughs and sputters for a while any you have to slowly let the throttle back out otherwise it will die. It runs for about 3 minutes then dies again. It smells like it is burning rich. If you let it sit for about 2 hours then it will start again and this whole mess starts all over again.

ANY insight would be helpful. Thank you.[/B]