I installed the latest flywheel with initial starting at 3 degrees ATDC. I have had to change starting procedure since then. I schedule Flyouts, and the plane will sit for say 1 - 1 1/2 hours. The engine core is still fairly warm ( even in colder climate ). It would not stay running the way it use to. After a few test, I found out if I give it a little throttle, it starts just fine and stays running. Hope this helps.