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Discussion Starter · #1 ·
I have been working with and tinkering with this tractor for a few weeks now and really like it.The only real problem I have been having is with the Onan B48M I can't seem to get the governor to work just right and I still have some oil leaking but nothing like before.So now the question, I have a good running Kohler M18 I would like to put it in the 1855A while I repair and reseal the Onan. Has anyone done this swap ? any tips or comments.I am very familiar with the M18 and its problems and it would only be temporary I don't use the front PTO only the three point. I am pretty sure the cage in the Onan's governor has broken and since I have to pull it anyway thought would be the best time to freshen it up in time for spring I hope.

Thanks, Bob
 

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I don't think it would be worth the effort being it would be a temporary repower, but it most certainly can be done. The issue will be connecting the hydro power shaft to the engine. The 2 engines have a different bolt pattern and centering ring size, so it's not a bolt up affair. You would have to machine an adapter plate to mate the 2 up. If I'm not mistaken, the M18 also has magneto instead of 12VDC fired ignition, so the ignition switch would have to be changed, or just use a toggle to ground for a kill switch.
 

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I don't think it would be worth the effort being it would be a temporary repower, but it most certainly can be done. The issue will be connecting the hydro power shaft to the engine. The 2 engines have a different bolt pattern and centering ring size, so it's not a bolt up affair. You would have to machine an adapter plate to mate the 2 up. If I'm not mistaken, the M18 also has magneto instead of 12VDC fired ignition, so the ignition switch would have to be changed, or just use a toggle to ground for a kill switch.
Yes, the M18 is magneto.
 
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Discussion Starter · #4 ·
Wow,that was quick ! I did know about the difference in the ignition but the drive shaft may be the sticking point .Since I will have both engines out I think I will test fit it anyway .I tend to hoard stuff and may be able to come up with something that will work.Once again, thank you both for the quick reply I really value your opinions.

Take good care, Bob
 

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I have a 1" shaft adapter for a Kohler and a Pulley adapter for an Onan. If I remember tomorrow I'll check those out.
 

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If you are going to rebuild the Onan and reinstall it, why put yourself through the extra work and expense of the repower? Do you need the tractor in the interim?
 

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Discussion Starter · #7 ·
I understand it might seem to be a lot of trouble but really no expense to speak of I already have the Kohler on the shelf. The Onan has to come out and to test fit the M18 just a matter of sticking it in there.I admit most of my experience has been with Cub tractors that's what brings me here to the experts.I like to have at least one tractor running around the place for pulling or dragging things .Not the end of the world if it's down for awhile.I guess I will have to see how it works out I will keep everyone posted .

Thanks again all for the thoughts and comments,Bob
 

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Easy solution. Buy another tractor to use while this one is down for the rebuild. Also I think you may find that Onan parts can get real expensive fast. Good luck.
 
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Discussion Starter · #10 ·
It has been awhile since I updated this post ,I have been using the 1855 with a big spring on the carb to keep it from over speeding.I found another engine for parts so was time to fix it .First I stripped the needed governor parts from the parts Onan I had to press the cam gear off the camshaft. Next was pulling the engine from the 1855 ,pulled the tins and flywheel off and found the exploded governor when I removed the cam cover.I swapped in the new/used parts and buttoned it all up.That is where I stopped for the day,tomorrow I will finish cleaning things up and set the engine back in and see how it works.I never thought to take pics till just now so only have the engine hanging on the lift and an empty dirty engine bay.

Bob
 

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It has been awhile since I updated this post ,I have been using the 1855 with a big spring on the carb to keep it from over speeding.I found another engine for parts so was time to fix it .First I stripped the needed governor parts from the parts Onan I had to press the cam gear off the camshaft. Next was pulling the engine from the 1855 ,pulled the tins and flywheel off and found the exploded governor when I removed the cam cover.I swapped in the new/used parts and buttoned it all up.That is where I stopped for the day,tomorrow I will finish cleaning things up and set the engine back in and see how it works.I never thought to take pics till just now so only have the engine hanging on the lift and an empty dirty engine bay.

Bob
Wish you had pics of the rebuild! Be nice to see what's in there!
 
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Discussion Starter · #12 ·
Well I finished up putting the engine back in and got her all hooked up,started right up and now the governor works!! I still have some fine tuning to do not sure when that will happen but much more usable now.I know I should have taken some pics ,I like to see pics so I promise next project .I just wanted to take advantage of a rare Jan. warm spell here in the Poconos.

Take good care, Bob
 
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