Forget WD 40, Forget expensive after run engine oil sold in little bottles. Have you noticed it is usually red in colour? I buy my after run engine oil by the Qt from the local automotive store for about $4.00. There they call it transmission fluid. Have you noticed it is usually red in colour?

I would have to question air leaking in through a front bearing. The air would have to leak in through the fit between the crankshaft and the crankcase. Crankcase pressure would push the air the other way. Which is why you get fuel coming out of a front bearing when the engine is running.

Ed S