720 wont stop accelerating help!

The other day i went to get gas and i was goin up a hill and when i let off the gas it wouldnt stop accelerating. so i finally got to the side of the road and shut off my engine. Now when i start it it revs up to about 4,000 rpms and keeps goin up. anyone have this problem? maybe linkage is stuck or something? i checked out the throttle cable and it was fine not stuck or anything. anyone have any ideas of what would cause this?

Maybe your float is sticking? Try tapping on the throttle body/carburator and see if that makes any difference.