Small Engines (Lawn Mowers, etc.): Kohler 23 HP Smokes, kohler smoking

Question
I think last year i overheated my Cadet 23 hp Kohler bagging leaves, this year it is smoking quite a bit and using oil, at 3yr old and 450 hrs im out of warranty, and i assume rings in one cylinder. One plug is clean one is oily.  About how much should i pay mower shop to hone and ring one cylinder? i realize it would be a very approximate figure.
Thanks
Larry

Answer
The entire engine has to come apart to do this, if that's the problem.  We charge $300-500 to rebuild twins, plus parts.  It's about a 6-7 hour job and maybe longer being on a Cub.

But I wouldn't have anything done until I had a leakdown test done.  You may not have anything more than a bad valve seal or a bad head gasket.  Any competent shop can do a leak down test.  We charge $65 to do this test on a twin.  I don't know how that compares to your area.  A leakdown test should show the exact problem.  Thanks, PK.