# Kohler Magnum M18S Overhaul



## artbuc (Apr 19, 2010)

Anyone out there ever tear down one of these? Any tips? Thanks.


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## 30yearTech (Sep 14, 2006)

You can download a service manual at the Kohler website.

www.kohlerplus.com


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## artbuc (Apr 19, 2010)

30yearTech said:


> You can download a service manual at the Kohler website.
> 
> www.kohlerplus.com



Thanks. I have the service manual but nothing beats real experience.


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## 30yearTech (Sep 14, 2006)

artbuc said:


> Thanks. I have the service manual but nothing beats real experience.


I have been through several Magnum series engines in the past, but it's been awhile since I have run across any equipment with these engines anymore. They are very similar to the Briggs opposed twin engines. I can't recall of anything special to keep an eye out for, these are very good engines and never really had any issues that I can recall, but since they were mostly found on premium units I did not see them all that often.

If you have any specific questions once you get started on your overhaul, post them and I am sure myself or someone on here will be able to assist.

Best of Luck....:thumbsup:


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## artbuc (Apr 19, 2010)

30yearTech said:


> I have been through several Magnum series engines in the past, but it's been awhile since I have run across any equipment with these engines anymore. They are very similar to the Briggs opposed twin engines. I can't recall of anything special to keep an eye out for, these are very good engines and never really had any issues that I can recall, but since they were mostly found on premium units I did not see them all that often.
> 
> If you have any specific questions once you get started on your overhaul, post them and I am sure myself or someone on here will be able to assist.
> 
> Best of Luck....:thumbsup:


Thanks. This engine has about 1200 hours onit. It starts and runs great. Burns very little oil and has good compression (100/105 psi cold). About 3 years ago I had to replace one burned exhaust valve and seat.


The reason I am going to tear her down is to replace the thrust washer. I have 0.025" endplay compared to the Kohler spec of .002/.0014". A couple years ago I had the electric clutch apart to clean up the faces. When I put it back together, I did not have all of the parts stacked tightly together up against the crankshaft shoulder. As a result, when I engaged the clutch, I was loading the crankshaft which (I believe) caused the thrust bearing to wear prematurely. Can't believe I did that, but I did.

In addition to the thrust washer, it has been suggested to replace the governor gear and piston rings. Others said do a complete overhaul although I don't know what that means.


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## justin3 (Apr 10, 2007)

A complete overhaul involves boring out the cylinders, installing oversized pistons and rings, new undersized connecting rods and re machining the crankshaft. All new gaskets + seals, new valves and seats ect ect.


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## artbuc (Apr 19, 2010)

justin3 said:


> A complete overhaul involves boring out the cylinders, installing oversized pistons and rings, new undersized connecting rods and re machining the crankshaft. All new gaskets + seals, new valves and seats ect ect.


Wow. For an engine that is in excellent shape except for excessive endplay, I think this is major overkill. The person who recommended a complete overhaul did so for 2 reasons: (1) do it now because Magnum parts may not be available much longer and (2) the engine would be good for another 25 years. I can't speak to parts availability but I will be using this tractor for another 5 years max so I don't need another 25 years. Of course, I'm not sure if the person recommending a complete overhaul was thinking about all of the items you mentioned.


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