Small Engines (Lawn Mowers, etc.): oil consumption, blown head gasket, crankcase pressure

Question
My dad has a CV15S veritcle shaft engine in a Toro rider started to use oil all of a sudden never used oil before this a 10 year old machine and may have run out but all would quiet down when refilled now it smokes like crazy compression is 35 LB took off valve cover and a cup of oil came out found a piece of head gasket in cavity leading back to crankcase looks like return hole back to crankcase is pluged pulled head I see no scatches in cylinder walls crosshatch design is still there should I pull piston to check for broken ring or this was just because of blown head gasket / pluged oil return ? thanks Jeff

Answer
What you see plugged is the crankcase breather.  Replace it and the gasket.  When this is plugged you have positive crankcase pressure in the engine will pump oil into the combustion chamber.  Thus the smoke.  Yes replace the head gasket, be sure to torque the bolts properly.  I do not believe you have a broken ring, because there are no scratches in the cylinder wall.  Be sure to check for leaks at the crankcase gasket upper and lower oil seals dipstick tube and dipstick O-rings.  I think this will solve your problem good luck.