I almost hate to ask this question seeing as how my life has been spent operating very large aircraft piston engines but I cannot see what harm might occur to an engine when the CC oil level is allowed to be higher than the full mark...the only harm that I can see might be a hydraulic effect which might burst the pan etc. I suppose there might be issues with allowing the 'big end' to ram through solid oil?. In any case I bought a new lawn tractor to mow a fairly large lawn that I just acquired and after mowing it a few times I thought I should check the CC oil level...well well!...it was super overfilled. To give you an idea, with the bottom of the stick at 'zero' the add mark at 8, the full mark at 10 they had filled it to about 30 or so!...there's several warnings in various places (one right on the stick) which says "Warning!...do not overfill".
For the life of me I can't see what it could harm...any clues?...
(I'll reduce the level before running it any more though)