I rebuilt a 1978 Kohler 241-S single single cylinder (12) hp. two years ago. It is in a Simplicity Tractor that use to plow snow. I had some deep heavy stuff last weekend, and something happened that has never happened to me before. While running, the engine's tone changed from full bore to slowing down with no change of the hand throttle on my part. So I tried to throttle it down even more, and it would not respond. After an expletive on my part, (it was aboutr 10 degrees and I was a hundred yards from the garage, I just put it in reverse and backed up till I was inside. THERE I tried again to throttle it down, with no luck. Had to turn it off with the key. I let it cool off some, and tried a restart, would not budge the engine to turn it over. If this engine seized up, what is the best way to break it loose without taking the engine out and completely apart? (There was and still it plenty of relatively fresh oil in it. I've never had an engine sieze that was full of oil, so I am mystified. I put a pipe wrench on the crank stub that sticks out in the front, but I knew better than to put too much torque to it, but 20 ft pounds didn't do a thing.

 

I would drain the oil an check for aluminum filings. The rod bearing probably went out. If you find filings you'll have to take it apart.

 

That is easy enough. will do...

At least I know how to take it apart.

thanks!

 

The way it happened, I would suspect a journal bearing seized. Did this have a ball bearing on the PTO end? Try tilting it to the pto side, then over to the flywheel side so that the oil gets to them and put a pipe wrench on it and rotate it backwards. It's already seized, so what more are you going to hurt? If the PTO side is what is seized, then you'll need to break it loose anyway to get the cover off unless it has a ball bearing there.

 

As I remember, there are two ball bearings in races on both sides. I will have to get this engine out of the tractor to tilt it, but if you think I can save it after breaking things loose it will be worth it. If it does break loose should I do something else besides just changing oil and trying to start it?

 

Is that linked to the transmission with a u joint or a belt? If it's a u joint the problem may be in the transmission, not the engine. Maybe you should try to separate the engine from the driven side first.

 

If it is the engine, I'd be pretty leery about running it after seizing. When one seizes, it usually galls the metal somewhere and it comes apart shortly after nearly every time. If it's ball bearings on the shaft, then you should be able to slide the cover off and inspect unless the bearing race seized and the crank spun inside the bore. Then it may have galled and might make it difficult to disassemble. Hopefully a bearing race came apart and locked up on the pto end and all you'll have to do is pull the sump cover and replace the bearing.

 

There is a u joint (rubber disk with bolts) easy to disassemble. Ill get it apart next week or sooner an post what I find. 10-4 on the galling, Cheese, I get it.

Thanks

 

Got the Kohler apart today, and I found the smoking gun, (along with shell casings and video survailanace.) EVERYTHING loosened up when I took off the rod end nuts. I could see from the bearing surface in the rod end, and the rod too, where it had galled, or scored or whatever you call it. It made some marks on the crankshaft, but I have a guy who will know what do do about that. It still mystifies me as to why a new rod would tie up like that at 10 degrees and plenty of oil, The last guy to touch that does not work for the rebuilder any more, so I can't get in his face about it, but i'm thinking that it was not torqued properly?

 

Since it lasted two years, it may come down to cold weather, thick oil and if the oil splash was still intact on the rod cap.

 

Could be improper torque or just what marbobj indicated. Good thing you took it apart... that wouldn't have held up long and might have damaged the engine when it broke. You can take the transferred aluminum off of the crankshaft with strips of emery cloth and some patience. Are you running 10w-30 in cold weather?

 

It got a fresh oil change of 10w30 last fall. So I just don't know. If I can save the crankshaft, I can live with the connecting rod replacement. No visible damage anywhere else.

Thanks for the replies!