I have newly rebuilt my complete engine crankshaft and all. I had it running good for a few hours when it was cold. Rode good and hard. Tried to start the next day and would idle but when you gave it gas it died. Try to start it back and it acted to have no compression. If you let it sit for 5-10 minutes it will start back and idle like before then die and lose compression again.

What could be the issue??? I’m Lost.