Kohler CV22S spec 75534
Craftsman 917.273080

Brief history.
Owner was unable to start mower, had inlaw tell her it was beyond repair.
Battery removed and mower set inside storage building for several months before I looked at it.
Battery cables covered with rust, cleaned them, connected battery charger-starter and mower started with little trouble, but blew white smoke from exhaust, and observable evidence of oil leak from around exhaust connection to block.
Ran fine with no load but continued to blow white smoke for several minutes before I shut it off and loaded onto my trailer.
Muffler and exhaust appears to have been replaced or repaired with a rigged replacement, including coat hanger.
I personally used the mower for her, last season and it was running fine with no smoke while I used it then.
Have no idea how many times it was used between the time I personally used it last and the time it was stored away as irreparable.

Told her from the start that I might not be qualified to do anything with the engine, but would try.
So here I am trying.
Any suggestions on what to look at?

 

Did you check the oil level? What does the oil look and smell like?

 

Oil level is slightly above midway in the pattern.
Smells like oil, no gassy smell, and is dark at the tip but clean higher on the stick.

 

I think I would get the oil level up to max, then start and run it for 15 or twenty minutes to see if the smoke would clear up. It may have been tipped on its side or on end and oil got into the combustion chamber. It would take a while to get it burned out, especially if it's in the muffler.

After running it for twenty minutes, check the oil and run it another twenty.

 

Could it be that some water found its way into the oil sump; and now that it has run for a while, been emulsified into the oil . . . . explaining the change in color from top to bottom on the dip stick ?

That would still create a bit of steam in the exhaust, like when you blow a head gasket on a water cooled engine.

 

Changed oil
ran it for ten minutes or so.
thick heavy white smoke with less gas.
Smoke thins out with full throttle.
No significant difference in smoke while driving.
Obvious oil leak around exhaust port from left, facing tractor, cylinder.

 

I would like to offer my sincere thank you for all of your help.