Just guessing. An engine needs...fuel, air, compression, spark. You have everything but fuel when you need it. It fires when you dump fuel in the throttle body but won't run, you've got fuel delivery problems. I'm betting it sat over the winter and clogged stuff. Not sure where ya get the idea of a broken ring. It will still run with a broken ring if it doesn't sieze, might run ****ty, but it'll run. As always, if I'm wrong please let me know. Wayne