If you do use a sealer, Ive had great luck over the years with Three Bond. Its a hi grade lite silicone based sealer. Its a lil spendy but totally worth it.
I always use it on cases and the base gasket. I also use the spray copper coat on the head gasket. This is on the Gen III 250r.
Shart Guard .......Use it !
Pink Powerwheels Barbie trike
Wamo Big Wheel with a solid trikecycle front tire
Mini bike 3hp Briggs and Stratton with cambells soup can exhaust
Schwinn stingray with coaster brakes
1985 Crash and Burn champ
1st place National Endo Championship