Author Topic: Onan 24 Rebuild Project (Read 1339 times)

Bodger · « **on:** November 20, 2011, 09:01:15 AM »

This is to update a post from back in the summer. My 95' LTHD40 Onan had about 6000hr and was still running but had seemed to be loosing some power and using more gas. I pulled it off and picked up a Kohler 30hp (very low hrs from a Cooks) so I could continue to run while working on the Onan. Finished this weekend. The Onan had always used Mobile 1 synthetic and showed virtually no wear when pulled apart - bearings looked fresh and less than half a thimble full of gunk in the bottom of the oil pan. I found a place that stocked everything, seals, gaskets, bearings, pistons and rings (only a little more over the cost of just rings). The cylinder only required honing and everything went back together pretty quick (you are not supposed to have any leftover parts). While I had it off I replaced the rubber under the engine mount. It's bolted back up, everything realigned/adjusted and running like it was new over 16 years ago.
Overall: The Onan is a little heaver and is only a 24hp but to me seems stronger than the Kohler it sounds like a Harley. The Kohler is a good engine, more hp, sounds like a Yamaha and is very fuel efficient. It was fairly straight forward retrofitting it to the WM - shims and rewiring and rigging a throttle. I like the idea of keeping the mill stock with the original engine. There is really not tech support from either company, Onan is now Cummings and the lady that answers the phone at Kohler does not offer tech support. Parts are available for both and both are costly but that is the price for being in business. Don't throw away that Onan, they are rebuildable - for less than a new motor and it is certainly worth the effort.

sawguy21 · « **Reply #1 on:** November 20, 2011, 12:50:13 PM »

Were the valves in good shape? If it was not burning oil I would have serviced them along with a tune up and called it a day. Onan always had very durable engines

Bodger · « **Reply #2 on:** November 20, 2011, 05:26:33 PM »

The machine shop cleaned up the valves and surfaces. I was concerned about the rings because it felt like it was not as strong as it should have been.

jason.weir · « **Reply #3 on:** November 23, 2011, 02:15:41 PM »

Bodger,

Where did you find the parts for your Onan? I've got one I'm looking for parts for..

Thanks,
Jason

Bodger · « **Reply #4 on:** November 23, 2011, 09:32:26 PM »

A place online called Enginemasters (enginemastersinc.com) Woodmizer has a few parts but not what you need for a rebuild.

jason.weir · « **Reply #5 on:** November 26, 2011, 09:52:27 AM »

perfect - thanks!!

-J

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