Small Engines (Lawn Mowers, etc.): Tecumseh smoking under load..., oil additive, tecumseh engine

Question
I have an old Ariens tiller w/tecumseh engine.  Idling or running at higher speed when not under a load there is no smoke.  When I put the tines in the ground it smokes like a tar-kiln.  I haven't done a compression test.  What should compression be, and if that is OK what then?  Valves?  Thanks.

Answer
Very few mower manufactures provide compression specifications, especially 4 cycle engines.

Tiller engines wear faster than mower engines because tiller are always ran in the dirt.

I would bet the valve guides and rings are wore causing it to smoke.  The only solution is rebuild or a new engine.

How old is the engine?
Have you tried an oil additive?

Let me know.
Eric

On a side note, Tecumseh engines will run will very little compression...they'll just smoke and not have any power.