The oil is all over the parts !!-----It just does not disappear when only dry air starts coming through the engine !!-----These tall tales of damage when running out of gas just won't go away.----Proof that the concept of mixed gas / oil is not well understood !
The factory rebuild kit is available all day long.----Many motors use the same rebuild kit !! ---Easy to find.-----About the only thing that goes wrong is the diaphragm.----Also easy to find.
It is a drain hole for a cavity.----Prevents freezing / cracking.------Normal for a 2 stroke to leak some oil there.------I have said it many times.------The mixing of gas and oil and operation of a 2 stroke is not well understood.
Don't waste your time on the sparky things.----Take the cylinder head off.----I do not think this motor will run without major surgery.----You will not like what you see.
The 20 HP was still marketed in CANADA up to 76 I believe..----It is as simple as that !!-----Not sure why that is an issue for you.-----Same ignition as the 25 HP models !!
Model # is ?----How did it run for you last season ?-----Need to post compression numbers.-----Does spark jump a gap of 3/8" or more ?-----Check flywheel key.-----Pushing key in and holding it in while cranking it over ?