We had a few problems with some of the Fel-Pro gaskets early on and got away from them. You may want to check the intake gaskets to see if they are leaking. I would remove the carburetor and look into the intake for
oil. I would also run a compression check and leak down on the engine to see if all seems ok there. Let me know what you find out and try these few things before you pull the engine.
If you find something wrong with the engine I will be happy to work with you on fixing the problem. Call me at 870-246-7460 if you would like.
Thanks, Keith Craft