It's confirmed, blew a head gasket on the LT15go.

Brad_bb · February 14, 2021, 10:39:55 PM

I first noticed the hiss of a leak back in Aug or Sept . when milling at my other place. This engine only has 432 hours on it. I finished on Nov 1. and moved the mill back to my old place. I procrastinated and probably only milled about 6-10 days by the end of the year. Milled a few more days in Jan, then had a back issue. All the while the leak was getting worse. I thought it was in the exhaust - manifold to head, but turned out it wasn't. After being out for 2-3 weeks I tried starting the mill and it wouldn't fire. As I was cranking it I was listening a little better trying to get a fix on where it was coming from. Got my hand back by the exh flange but it wasn't coming from there but rather just below from behind the sheild. Now I was sure it was a head gasket so I started disassembling things so I'd be ready for the head gasket change. Sure enough, There was the blow out, where you can see oily residue on the fins.

Tomorrow I have to order the parts - head gasket, maybe head bolts if they are the stretch type? I have to find the torque specs. Talking to Woodmizer last week, I found out that the service techs don't work on engines? Which surprised me. I was told that issues like this I have to find a Kohler dealer? We'll see what I find out tomorrow.

sawguy21 · February 14, 2021, 11:00:43 PM

Here you go
http://www.smallenginesuppliers.com/html/engine-specs/kohler/CH18_CH26_CH730_CH740_CH745.pdf

Percy · February 15, 2021, 01:23:34 AM

I had the same basic motor on my edger, mine was a 25 hp carb version that I replaced head gaskets a couple of times and valve push rods as well, If its not under warranty, you could do it yourself. Once I had the parts, I gave myself a day to do the job and it didnt take nearly as long as I thought it would...Regardless, I hope it goes well for you. First head gasket failure was at about 3000 hours for me......A guy told me that had I re torqued the heads at about 100 hours, it wouldnt have happened....I never got the memo...heh....but I guess it wouldnt hurt...

celliott · February 15, 2021, 04:25:00 AM

I did the head gaskets on the Kohler ch22 in my toro lawn tractor this summer. The worst part was pulling the engine. Honestly not a bad job at all.
But if you have warranty on it, better pursue that.

Brad_bb · February 15, 2021, 08:15:46 AM

No warranty, mill is 2014 model year. When you guys put a new head gasket, the head was ok, not warped? Another question, Do you need the engine in any certain position of the stroke before removal? I'm also not sure how the valves are in there? Do you do anything so the valves are closed and not under pressure? Not sure how it's configured inside? Do you need to remove rocker arms and push rods?

Ben Cut-wright · February 15, 2021, 12:48:19 PM

You have asked enough questions to indicate you should do a bit more to educate yourself in this repair. Head gaskets are a common failure on these engines. There are more than enough resources online to cover this fairly simple job. There are also a few things that you should check and be aware of. The push rods do have a tendency to bend. Check them for tip damage and bending. The lifters have a tendency to collapse or go rigid/stay pumped up. The lifters should have the oil depleted before installing the rockers. When you take the rockers off the pressure on the push rods is relieved. If the lifters are bled down they will not bend the push rods when the rockers are installed. You didn't do the engine any favors by continuing to operate it. Check the valves very closely. A blown head gasket can contribute to burned valves, usually the exhaust. I would strongly suggest to replace both head gaskets and any other related components that may be compromised or faulty on both cylinders. Check the spark plugs, change the oil and filter, and I use new head bolts for added security. Use the correct engine oil, very important in these engines. There are service bulletins online that explain the oil requirements.

Not a difficult job, you can do it I think.

Brad_bb · February 15, 2021, 04:34:51 PM

I looked on youtube and watched videos for the head gasket replacement, so now I'm an "expert". :D

Working on getting the parts now. They apparently have a gasket kit for head gasket replacement and judging from the number of vids on youtube of this, must not be an uncommon thing. Fortunate that its a mill application. I won't have to remove the engine to do it and enough room to work around. It's also fortunate that It's in a heated shop! I'll get all the surfaces cleaned up and carbon removed in the combustion chamber.

I'll inspect my pushrods etc, but with so little hours, I'd hope they are fine. Thanks for the responses fellas!

Percy · February 15, 2021, 09:28:32 PM

Get a hold of BandmillBandit(Wes) concerning the lifters for this engine. Had an easy remedy I can't recollect at thus moment.

donbj · February 16, 2021, 11:53:25 PM

Quote from: Percy on February 15, 2021, 09:28:32 PM
Get a hold of BandmillBandit(Wes) concerning the lifters for this engine. Had an easy remedy I can't recollect at thus moment.

I think he said they were 350 chev engine lifters

Brad_bb · March 04, 2021, 07:15:14 PM

A little over a week and a half ago I pulled the cylinder heads and did a thorough cleaning of the combustion chambers and piston tops. They had a good layer of oily buildup.
Non operator side
After- I forgot to take before pics

Operator side- after and a before of piston

I used a dremel with fine scotch brite wheels to remove the build up and clean the gasket surfaces. I also used lacquer thinner on paper towels to help clean the build up off both before and after using the scotchbrite. I had to use a dremel wire wheel to get in come tight places around the plug hole etc. I did my very best to make sure it was all clean and blew it out with compressed air, and did a final wipe down with lacquer thinner. I then took a very small amount of oil on a wood stirring stick and carefully dabbed it around the perimeter of the piston top. I wiped any excess with a paper towel. Re-assembly went well. I did use my snap on digital 3/8" drive torque wrench on the head bolts, spark plugs, valve cover bolts, and intake bolts. I used new gaskets on the valve covers, intake, and exhaust. Originally I was just going to do the one side that was leaking, but after seeing the build up, decided to do both. I had to go back out and get another head gasket kit. After finishing, I was missing one of the spring clips that broke for the fuel pump. Also I needed to leave for my new place to organize my new storage building and then receive/unload 6 semi-loads of hay over the course of the next two weeks and stack them in the building. So I managed to get back home for a day an a half and I just barely had time to vacuum all the saw dust out of the battery box, reinstall the battery, put the new clip on the fuel line, and try starting it. Success! Overall, I would saw that this job was not very difficult. Just keep track of your hardware, torque your bolts correctly, and keep things clean.
Starting after head gasket replace Kohler command twin CH620 - YouTube

Brob1969 · March 04, 2021, 08:40:16 PM

Good job. Looks like you were pretty thorough going back together.

Nebraska · March 04, 2021, 08:42:45 PM

Six loads of hay!? How many horses are you feeding? Glad you got the motor up and running.

Brad_bb · March 04, 2021, 09:08:48 PM

@Nebraska 12 horses. We want a year's worth of hay in the barn at least. These are 350lb 2'x3'x6' bales. Not a size that most people see, but they work very well to move and load with a skid steer and to flake off. In the long run, I don't want to store hay in this building, but it's the only one of 3 that's finished and ready to take hay. The pallet racking uprights are 12' for reference. There's concrete under pallet rack and the wood stacks on the right.
1st load (only pic I've taken so far)

thecfarm · March 04, 2021, 09:20:49 PM

Saw that size bale in Lancaster, PA.
Glad all is well with motor and feed.

donbj · March 05, 2021, 12:00:08 AM

430 hrs. I consider that pretty good! I blow a gasket much sooner than that :D

moodnacreek · March 05, 2021, 02:30:17 PM

I grew up in an era of engines that never blew head gaskets. The old guys back then would tell you that the gasket was not the problem, there was something wrong with the engine. That was true back then. It sounds like the younger set thinks we [old people] should know the head gasket won't last. I guess they are right but it is still not right.

jpassardi · March 05, 2021, 02:43:10 PM

Quote from: moodnacreek on March 05, 2021, 02:30:17 PM
I grew up in an era of engines that never blew head gaskets. The old guys back then would tell you that the gasket was not the problem, there was something wrong with the engine. That was true back then. It sounds like the younger set thinks we [old people] should know the head gasket won't last. I guess they are right but it is still not right.

You're right, there is a design or material issue. Could be gasket material or quality of, deck surface or flatness issue or inadequate clamping load - possibly a combination of each.
Unfortunately, the manufacturer Kohler knows exactly but isn't going to eat the costs because it's past any warranty.

Brad_bb · March 05, 2021, 07:55:18 PM

This was the first blown head gasket I've had on anything. Cars, tractors, trucks, mower, chainsaws... first time. It was nice that there were vids on youtube of other guys doing it. Unlike the old days you get to preview the job. Manuals are on line too, which is nice.