Kohler m18 engine renew cylinder barrel and head

[BESTDOGEVER 218]

My Kohler m18 is burning a lot of oil and I suspect bad intake seals as well as rings.I have a cylinder, piston and head assembly that looks really good. My thought is decarbon the head and valves, replace the rings and intake seals then swap them out with the original ones. All this is assuming the cylinders are not worn. They look really good no scratches etc. Has anyone done this and what results did you have 

 

[johnnymag3 2,445]

Following.....

[pfrederi 17,148]

2 hours ago, BESTDOGEVER said:

My Kohler m18 is burning a lot of oil and I suspect bad intake seals as well as rings.I have a cylinder, piston and head assembly that looks really good. My thought is decarbon the head and valves, replace the rings and intake seals then swap them out with the original ones. All this is assuming the cylinders are not worn. They look really good no scratches etc. Has anyone done this and what results did you have 

 

If you have only one extra jug do you plan on just reringing the other cylinder. Not sure I follow.  Have you downloaded the M18 SM

 

 

Edit:  If you are burning a lot of oil i would suspect you need more than just the rubber seal provably need new valve guides...at least mine needed them and it wasn't even burning oil....

Edited March 25, 2022 by pfrederi

[BESTDOGEVER 218]

I have both units and plan to make sure they are good before swapping them, need to find shop to check them out. Not easy anymore all the parts stores that did machine work got out of it 

[pfrederi 17,148]

55 minutes ago, BESTDOGEVER said:

I have both units and plan to make sure they are good before swapping them, need to find shop to check them out. Not easy anymore all the parts stores that did machine work got out of it 

  Good luck...  Also at some [point in production they changed from 45 to 30 degrees valves... Not an issue if you move the whole jug over. but does affect the valve clearance settings...

 

You may want to check out my post about overhauling an M18 $$$$  over under parts be hard to find....

 

 

[Achto 26,576]

If you install new rings with out scuffing the cylinder, you will not have gained anything. Your new rings will not seat in the cylinder. At a very minimum the cylinders will have to be ball honed to break the glaze and establish a good cross hatch before installing the new rings.

 

Here is one source for a re-ring kit for a M18, $287 for OEM, $100 for aftermarket. Both include all the parts gaskets & seals that you will need.

http://www.psep.biz/store/kohler_rebuild_kits.htm

Edited March 25, 2022 by Achto

[BESTDOGEVER 218]

Yup I knew that (good reminder though),my biggest concern is seeing what the measurements are on the replacements to see if all of this is cost effective. Time and effort wise if all the variables line up its a one day job and my 4/518  franken horse is up and ready for another 1500 hours . If not plan b is look for a good used engine. Either way I keep present engine full of oil and working till solution is found 

[BESTDOGEVER 218]

Update on this. Everything went south really quickly, I ended up with a bad oil leak and even more burning. Still couldn't find anyone to check/bore the doner cylinder barrels for less than my 3 favorite grandkids. Long story short I swapped the cylinders and pistons put in new gasket set held my breath turned the key and so far the beast is running strong with no smoke or leaks we will have to see how it goes but it seems hopeful. 

[johnnymag3 2,445]

I have alot of M18 Parts..........Good parts

 

[BESTDOGEVER 218]

Thanks, good to know. I  still have a few good parts left from my doner engine. Hopefully enough to outlast me. 

[BESTDOGEVER 218]

Just a quick update, 4 months in ,20 plus hours of more than average mowing in warmer than usual temperature and it has used about 50-60 percent less fuel and I have only added about 8 ounces of oil compared to the previous 24-32 ounces per mowing. Not having access to measuring tools or anyone close by able to do the work I checked the rings for any damage, finding none I ran  the pistons back and forth in well oiled cylinders they left the cylinders clean in both directions. At that point I decided to clean everything up and put in new gasket set and see what happens. Not exactly high tech but it is what my dad would have done and so far it worked. Pops worked on everything from model t's to the fire breathing monsters that were the chrysler b block engines of the 60's  so I figured what can it hurt. 

[Heatingman 941]

A telescope gauge set and a micrometer can be had for about 100 bucks.

 

Anyone mechanically inclined that can learn to use them effectively.

 

Gotta remember your not building a race engine, so Starrett and or Mitsutoyo instruments are not a necessity.

 

But even a quality used set of those can be had fairly inexpensive. 

 

 

[BESTDOGEVER 218]

I don't mean to come off as anti technology but my reasoning on all this is; to rebuild this "properly " means 600 plus dollars and time that I didn't have into a 35 year old generation 1 engine, which left me with a choice of either find a workable way to get a good result or get a good more up-to-date engine. First, I had gotten the parts engine from a reputable dealer and trusted his judgment that the parts were in good condition. The checks I did confirmed that. As I said I am not against doing stuff properly but I have seen many times that old school will beat technology. If time and or money aren't an issue in the equation by all means do it by the book. But my reason for sharing this is that you can get a good result using a different approach. I will be the first to say that the results are better than I expected, and for what I had invested even if they were not so good I at least bought more time to find a better solution. 

[Snoopy11 5,713]

On 6/25/2022 at 3:31 PM, BESTDOGEVER said:

Long story short

I wish you would tell the long version... I'm not really comprehending what you did here...?

 

Don

[BESTDOGEVER 218]

Ok back in June the annoying oil consumption went very quickly to I bet you can't make it back to the shed before I blow up. So with grass growing like crazy and no one really interested in working on checking/boring small engine cylinders I  did a thorough inspection of all the parts I was swapping from my parts engine checked the pistons fit in the bore by oiling them and running the pistons back and forth. Cylinders were clean no streaks of oil anywhere at that point I decided to go with what I had. For 20 bucks in gaskets I took a chance based on the details above and I have a good running engine as a reward. 

[Heatingman 941]

4 hours ago, BESTDOGEVER said:

I don't mean to come off as anti technology but my reasoning on all this is; to rebuild this "properly " means 600 plus dollars and time that I didn't have into a 35 year old generation 1 engine, which left me with a choice of either find a workable way to get a good result or get a good more up-to-date engine. First, I had gotten the parts engine from a reputable dealer and trusted his judgment that the parts were in good condition. The checks I did confirmed that. As I said I am not against doing stuff properly but I have seen many times that old school will beat technology. If time and or money aren't an issue in the equation by all means do it by the book. But my reason for sharing this is that you can get a good result using a different approach. I will be the first to say that the results are better than I expected, and for what I had invested even if they were not so good I at least bought more time to find a better solution. 

My point was a reaction to a statement you made that you could not find a machine shop to take a measurement of the bore.

 

I was just pointing out, that you can do that yourself and then have confidence in just swapping parts knowing that they are in tolerance. Or finding out your only real options are another motor, or the machine shop. 

Im glad that it worked out for you. 
 

 

Edited October 23, 2022 by Heatingman

[BESTDOGEVER 218]

It wasn't only not finding one to take a measurement it was finding one to work on it after 3 months of calling and checking with people who might have access to those places and then being in a 911 situation. I understood what you were saying I just wanted to clarify why I went that way, thanks for your input. 

[Moparfanforever 726]

Glad it worked out good 👍!!

 

Knowing my luck, it wouldn't have worked. 

[Snoopy11 5,713]

On 10/23/2022 at 10:31 AM, Moparfanforever said:

Knowing my luck, it wouldn't have worked. 

With a more thorough explanation of what was done on this engine... now I understand... and that is what I thought was done to this engine.

 

For it to work over the long term... those cylinders have to be round. Simple concept... but you get lucky when it works out okay... and it isn't impossible that it might ...for a while.

 

Let's say, for disclaimer, that it isn't impossible that you may just be biding more time waiting for the rings to get eaten if those cylinder walls are not round from top to bottom of cylinder. It could be ever so slightly cone shaped, and it isn't impossible that you will have more issues in the future. (not trying to me pessimistic... just simply stating a possible fact).

 

 @Heatingman had a very good point in this thread that I hope future viewers take into consideration. If you measure, then you know. If you don't measure... the possibilities of failures exist.

 

Don

[BESTDOGEVER 218]

On 10/25/2022 at 5:08 PM, Snoopy11 said:

With a more thorough explanation of what was done on this engine... now I understand... and that is what I thought was done to this engine.

 

For it to work over the long term... those cylinders have to be round. Simple concept... but you get lucky when it works out okay... and it isn't impossible that it might ...for a while.

 

Let's say, for disclaimer, that it isn't impossible that you may just be biding more time waiting for the rings to get eaten if those cylinder walls are not round from top to bottom of cylinder. It could be ever so slightly cone shaped, and it isn't impossible that you will have more issues in the future. (not trying to me pessimistic... just simply stating a possible fact).

 

 @Heatingman had a very good point in this thread that I hope future viewers take into consideration. If you measure, then you know. If you don't measure... the possibilities of failures exist.

 

Don

It's now almost a year later and I would like to thank all who shared their insights and share that with a winter of hauling wood and another mowing season under its belt the old girl is still under 1 quart of oil added and running well. Yes I got lucky but for 50 bucks +or minus which I have saved in oil and gas I'm happy and hopefully this old tractor will outlast me.