If you have turned it over it will let oil in the exhaust or if you have to much oil in it
Why Does Oil Come Out Of Exhaust On Lawnmower?
Blown gasket
Possible cracked piston also.
The rings on the pistons in the engine no longer hold much compression so oil blows by creating plumes of white smoke
The oil is breaching a barrier between the lubrication system and the combustion chamber. Bad rings or bad head gasket.