Overfill will come out somewhere....somehow....in the meantime, if it can't get out, it will get foamy, from being whipped by the crankshaft and then it can end up in the intake tract, by migrating through the crankcase ventilation system.
If system is tight it won't leak anymore if it's overfilled than with correct level. Also being a dry sump system as long as there is room in the tank for anything in the sump to be returned and for expansion don't worry too much about overfilling. Unlike a wet sump motor you won't lose any power.
i guess it would depend on how much overfilled u had. assuming u filled it to the top when the the oil gets hot and expands it is either going to come out of the cap(blowing off cap) or come out of the vent tube lubricating your rear tire. neither sounds very good to me. i sometimes get mine 1/4 inch above and have not had a problem.
i guess it would depend on how much overfilled u had. assuming u filled it to the top when the the oil gets hot and expands it is either going to come out of the cap(blowing off cap) or come out of the vent tube lubricating your rear tire. neither sounds very good to me. i sometimes get mine 1/4 inch above and have not had a problem.
Actually it is probably not the oil non return valve. I just had my clutch cover off. And while I was in her I thought I would load some oil in the tank and watch it. Mine has leak down issues but nothing fast maybe about 1/2 inch down in the tank overnight. Anyway it took a while because its a slow drip. It is the spray bar coming from the pressure pump and spraying the clutch basket outside probably insures the two primary gears get extra lube plus helps lube the rest of the clutch on the outside. Anyway thats where the leak down is.