On Fri, 09 Jan 2009 09:40:45 -0600, RoyJ
wrote:

This is the 12 hp Kohler K301 that is all cast iron. The output shaft
bearing is a standard ball bearing with a 1.574" ID and around 4" OD.
I've never seen such a massive bearing on a small engine. The flywheel
end is the same 7/8" that most similar engines use for the drive end. It
took two of us using a chain and sling to move if from the garage to the
shop, feels like it weighs around 100 pounds.

Everything looks good inside except for a chip taken out of the lower
cylinder, perhaps 3/4" square.

My local supplier has a piston, rings, and rod package for about $70.
I'll check for taper and all that, good chance I'll bore it oversize.
It's about due after all those years!

The engine was in a '64 Cub Cadet tractor that I've had since the '70's.
About every 10 to 15 years I hone the bore and put new rings in. That
little chore was scheduled for this fall, had one more 1/2 hour session
before layup. Blew on startup.

The cylinder fins were completely caked in dust, no air flow what so
ever. Suspect is was running way hot, burned the oil, finally grabbed
the rod bearing .


I hope your luck is better than mine.

I've tried this more than once with old Kohlers and not had much
luck.

First one I did it right. I had it bored and the crank ground. I
replaced every wear part (with Kohler brand not after market). Full
rebuild. I ran it one month when it threw the counter balance gear
through the side of the block. Moral of this lesson check the wear on
the timing gear. Unfortunately it's made on the crankshaft and can't
be replaced without a full crank (be sure your sitting when they qoute
you the price). If you have some wear on the gear and have the counter
balance gears my recommendation is to leave them out. It vibrates more
but if the gear happens to get on top of the tooth and snaps the shaft
like mine then it's not pretty.

I tried at least three other times after getting several of the same
engines in a trade. None lasted more than a year or two (though I
admit to cutting more corners on the later ones) . The last had the
chip you talk about out of it and it ran about 1 1/2 years before the
oil burning got bad enough I had to give it up.

I finally broke down and put a new 16HP Kohler on my old John Deere
mower. It's been running great for 10 years now (though I've noticed
it's been a little harder to start lately). That was another adventure
since John Deere didn't use a standard Kohler engine but rather had a
special oil pan to drop the engine lower over the front axle and had a
smaller out put shaft than normal. The special engine was $1600 when
the standard 16HP I replaced it with as $700.

Just a heads up of potential problems.