Got bit by the Kohler bug...

cobbr68 · June 08, 2020, 09:20:01 AM

I have an LT40 mfg 11/16. Kohler 26hp EFI engine. If you could point me in the right direction - which may mean take it to an authorized service tech in the Charlotte area - I'll do that.

I have about 160 hours on the mill and decided I should change the oil, plugs, fuel filter (air filter looked fine). The saw was running fine but I wanted to stay on top of maintenance. So I went to Autozone and bought the stuff (was that my first mistake?)

I replaced everything and then it started running poorly. Part way into a small white oak cant, the saw died. Symptoms are (no MIL):

1. Won't start or can barely start
2. Once it barely starts it may die or it may idle ok
3. If I engage the blade, it idles.
4. Once I disengage the blade, the mill dies with puffs of white smoke
5. If I start sawing, it dies.

So, I've:
1. Taken out the plugs and confirmed the gap setting

2. Put the old fuel filter fuel back on (I researched and realized the Kohler is 10 micron and Autozone is probably 80 micron)

3. Put Seafoam in the fuel in case it was bad fuel

4. Replaced the fuel in case the fuel was so bad that Seafoam couldn't help

Thx

Rick

Also, is it worth buying the Kohler diagnostic software and cable to better identify the problem?

Tom King · June 08, 2020, 09:45:24 AM

Not familiar with that motor, but I'd take the fuel line loose where it goes into the fuel pump, and see if fuel is flowing.

Make sure it's full of oil. I expect it has a low oil cutoff.

Since it was running fine before the service, something happened during.

ladylake · June 08, 2020, 10:31:05 AM

Check the oil level, they don't like to be overfilled. Steve

Gere Flewelling · June 08, 2020, 01:00:21 PM

I have that same engine in my mill. It has about the same hours on it as yours. Last year it developed a problem of running out of power half way through a cut. It sounded like it was skipping. I noticed the check engine light would come on whenever this would happen. If I shut the engine off and restarted it again, it would run fine until I got half way through a cut again. Is your check engine light coming on when this bothers? If so you can get it to blink out a code to help identify the problem. If you turn your key switch on-off-on, the check engine light should start blinking if there is a code. You have to count out the blink sequences to come up with a number. For me it ended up being a faulty oxygen sensor in the muffler. It doesn't sound like you have the same problem, but possibly you can diagnose it the same way. I have a service manual for this engine. If you can identify the code, I may be able to help you isolate the problem online. Good luck.

Southside · June 08, 2020, 08:40:18 PM

Perhaps @MartyParsons can provide some guidance.

Larry · June 08, 2020, 09:35:44 PM

My Kohler had similar symptoms last week. A squirrel bit into the fuel line and made a pinhole. Air entered the fuel line when it was running and when I shut down fuel leaked out making it hard to start. Simple fix.

The quick connect on the gas tank will do the same thing if the "O" ring is wore or if it doesn't lock tight.

cobbr68 · June 09, 2020, 08:56:04 PM

Thanks guys.

I swapped spark plugs but no change. It was interesting to see the difference in plugs. Both are new.

So I went and got another set...no change.

I now have a "crankshaft position error no signal" fault code 0337. :

DPatton · June 09, 2020, 09:11:09 PM

Are you sure you have spark at that bottom plug? Doesn't appear to have been firing.

Southside · June 09, 2020, 09:30:19 PM

Without knowing where the crank is an EFI engine may not spark at all, so that makes sense. Start with the sensor and wire, maybe it got knocked loose, torn, etc. during the maintenance. That's the easy fix and most likely source of the issue. You don't want to know the alternative.

YellowHammer · June 09, 2020, 11:42:50 PM

The only things that normally go bad when the engine is not running immediately after getting maintenance are the wires get moved, connectors lose contact, sensors get damaged, a battery short kills a component or sensor, inadvertent ground causing a short killing a component, or other basic stuff. Rarely does PM cause a true engine core issue.

Gere Flewelling · June 10, 2020, 07:45:43 AM

I do not have a WoodMizer mill but I do have that same engine on my mill. I think that before you repair this problem you will have to replace the original oxygen sensor. Kohler has issues with the originals and upgraded them. I had the same looking spark plugs over and over. New sensor and all problems went away. A plug and play repair.

cobbr68 · June 10, 2020, 09:00:54 AM

I've been speaking with a Kohler tech who is going to come out with his laptop/diagnostics eqpt to figure out what's going on. He did say that one black and one white plug like this may indicate a bad coil. He is also bringing an O2 sensor. The other thing that's interesting is that after the engine dies, I'll take the plug boots off to look at the plug. One plug is very hot to the touch and the other isn't at all. Doesn't seem logical to me.

VooDooChikin04 · June 10, 2020, 09:08:03 AM

To me the fact one is hot and one is cool seems logical when you see the plugs.. obviously one is not firing. If you're truly getting a crank position sensor code, then it makes sense as someone else has said that the engine won't fire if it can not determine the proper crankshaft position.

cobbr68 · June 12, 2020, 05:27:29 PM

Soooo...one spark plug was black and the other was white b/c the cylinder wasn't firing where the white one was located. The cylinder wasn't firing b/c of this:

MartyParsons · June 12, 2020, 05:35:19 PM

Hello,
I have seen this before. Kohler engines have hydraulic lifters. Some engine oils foam and cause the lifters not to bleed down. Causing this issue. 10W-30. Straight weight oil will do this. There are class of oils that should be looked at.
This is a knee jerk reaction to this failure. May or not caused the failure. FYI.

Marty

VooDooChikin04 · June 12, 2020, 06:27:24 PM

Dang! Could be worse. Glad you were able to get the problem found.

cobbr68 · June 12, 2020, 09:32:45 PM

Marty, I can't remember what oil I put in the mill. I'll check. That would be crazy if it was that finicky.

samandothers · June 12, 2020, 10:03:51 PM

Hmm, push rods should not be in 2 pieces, you must have gotten a special one.

Glad mystery is solved.

Marty that sounds kinda crazy!

. Not doubting you at all just wouldn't have suspected such.

pineywoods · June 12, 2020, 10:24:08 PM

Got bit by same bug on the 25 hp kawasaki on my mill. Would you believe ethanol gas. Not the ethanol itself but the water that usually goes along with it. Most small engines have no valve guides, just a hole drilled through the aluminum head. Aluminum head, steel valve stem plus water and let it sit for a week or so. Corrosion equals a valve stuck in the head. When you crank the engine, the weakest piece in the valve train breaks. bent broke push rod, bent rocker arm, bent valve or worst case a cracked head. We both lucked out

Bruno of NH · June 12, 2020, 10:25:58 PM

I run 5w-30 synthetic made for small gas engines in my mill.
It was a oil listed in the engine paper work that came with the mill.

dgdrls · June 13, 2020, 07:34:53 PM

Quote from: pineywoods on June 12, 2020, 10:24:08 PM
Got bit by same bug on the 25 hp kawasaki on my mill. Would you believe ethanol gas. Not the ethanol itself but the water that usually goes along with it. Most small engines have no valve guides, just a hole drilled through the aluminum head. Aluminum head, steel valve stem plus water and let it sit for a week or so. Corrosion equals a valve stuck in the head. When you crank the engine, the weakest piece in the valve train breaks. bent broke push rod, bent rocker arm, bent valve or worst case a cracked head. We both lucked out

Great info pineywoods, I can believe that. Non ethanol fuel is key or add ethanol treatment to "regular" fuel.
I add a shot of synthetic premix oil to my small engine fuel to make it a little more slippery as well.
D

Ben Cut-wright · June 14, 2020, 04:07:03 PM

Quote from: cobbr68 on June 09, 2020, 08:56:04 PM

I now have a "crankshaft position error no signal" fault code 0337. :

What was determined to be the cause of the CPS fault code?

cobbr68 · June 14, 2020, 10:37:23 PM

I did use 5W-30 instead of 10W. And I don't think it was synthetic blend. The Kohler specialist said that the Kohler brand is 10W synthetic blend. Note to self for next time...

Also, I did use non-ethanol. I don't usually use that in 4 cycle engines but I happened to this time. Not sure if either of those details contributed to this issue.

The mill is running fine now...finishing up a custom milling job on some white oak. Thankfully, the customer has been patient.

cobbr68 · June 14, 2020, 10:40:18 PM

Ben,

Great question on the 0337 fault code. I can't remember his explanation. I'll ask again and post it.

Rick

Ben Cut-wright · June 15, 2020, 10:05:58 AM

Quote from: cobbr68 on June 14, 2020, 10:37:23 PM
I did use 5W-30 instead of 10W. And I don't think it was synthetic blend. The Kohler specialist said that the Kohler brand is 10W synthetic blend. Note to self for next time...

Also, I did use non-ethanol. I don't usually use that in 4 cycle engines but I happened to this time. Not sure if either of those details contributed to this issue.

The mill is running fine now...finishing up a custom milling job on some white oak. Thankfully, the customer has been patient.

Your initial post stated you "have about 160 hours on the mill and decided I should change the oil". Was this the FIRST oil change ever for this engine?
I don't think the lower viscosity oil you selected for the oil change would have caused the damage immediately after the oil change. Oils with lower API service ratings than Kohler recommends can cause rapid damage. 10W-30 is the viscosity range most suited for your location. Just as important is the use of "API service SJ" or better oils.
Not sure what you meant by "don't usually use non-ethanol fuel in 4 cycle engines". Did you *happen to use non-ethanol in this Kohler when the problem arose? Did you *happen to use non-ethanol in the Kohler all along? Non-ethanol would be the better choice and using it should not have caused the current problem.
What did the tech say about 'cause and effect'? Was he satisfied the failure was simply a failed push rod? Did he recommend changing the oil you put in the engine?

Glad you got it running fine now.