Problem with a Kohler on a Walker Mower? Help?

[TOSLC]

I have a 99 Walker CGHS that has a 16HP VTwin Kohler. About 1700 hours and has run perfectly up to this point. I mowed two weeks ago and brought the mower into the shop hot, shut it off, and it Back fired. No big deal I went into the house not giving it a second thought. Well the next time I go to use it the mower only wants to run on one cylinder. To make a REALLY long story short I'll list what I've done to this point, and hope that someone has some idea's.

Two new Kohler Coils
Two new spark plugs (Swaped them from Cyl to Cyl - no change)
Flywheel Key is fine
Compression Checked (Cyl #1 = 120psi, Cyl #2 = 100psi)
Cylinder Leak Down - Moderate range (good for 1772hrs)
Cranked over engine with valve cover off - Both valve's moving

I'm at a loss here, and could really use some advice before I throw any more $$$ at it. Like I said I think it might of had something to do with the back fire because it ran perfect to that point. It's cylinder #2 that's missing out, and one more thing to add is if I cover the exaust port while it's running, it trys to fire that cylinder more often?

16Hp Vtwin Kohler
Family: TKH574U1G2RA
Model: TH16S
Spec No: 52518
Displ (cc): 520
Serial: 2816000761

[tomo]

hello, although i am not familiar with the 16hp twin if it is the same as 20--25--26 hp spray carb cleaner over inlet manifold where it joins to clinder head . This can be done while engine still in machine . This checks 4 vacumn leaks at the relevant cylinder .

Other way is also balance check . Principle is to see which cylinder is doing the most /least work .
1/ leaving both plugs in
2/connect inductive tacho to cyl to cylinder AA
3/ remove opposite cylinder spark lead and install spare plug .Earth to ground the body of the plug eg using jumper lead. Cylinder BB
4/ start engine and take reading of tacho
5/the cylinder BB work rate can now be checked note rpm drop compared to idle
6/swap tacho ,reconect BB ,install tacho BB, earth plug lead AA as described b4
7/ note rpm drop compare readings and you will find the cyl doing the least work

COMPRESSION CHECK --found best/consistant results if both plugs are removed first. Crank an even number of times. 130--150 would be nice.
7--9 compression strokes.


Check 4 presence of vacumn in crank case ,only small amount required if positive pressure, compression pressure is in the crank case via rings or head gasket .

Remote possibility is blocked exhaust on that cylinder

tomo

[TOSLC]

I'm 99.7% sure that cyl#2 is the one not firing. The engine actually runs better with the #2 plug wire unplugged, than it does with it plugged in. It won't run at all if you unplug the #1 wire (with #2 plugged in of course).

Spraying carb cleaner around the intake is an interesting idea though. Maybe the backfire blew out part of the intake gasket and it can't get fuel like it's supposed to? I'm at work right now, but I'll try it as soon as I get home . . . at this point I'm up for about anything.

Any help is appreciated and I will post back what fixed it.

[pugs]

This engine is not like the 20...25...30 whatever. This is Kohlers Overhead Cam engine. Honestly I have only ever seen one. It resides down the street from me on a Walker. Heck of a time finding the right air cleaner for it...LOL

Unfortunately I know very little about that engine. It could be an intake leak but its hard to say. 120 vs 100 for compression is a decent enough difference to be a bit concerned.

What type of leakdown tester are you using. What percent was the leakage. Moderate isnt really detailed enough. And where is the leakage air going? Intake, exhaust or crankcase?

[topsites]

You might not want to do this yet but before you give up, and you also need to do this during the early afternoon due to noise but...

Seeing how it backfired (through the muffler, yes?), it is possible something came off inside the muffler and is clogging...

So, remove the entire muffler but before you play with it, with the muffler off first inspect the exhaust port to make sure it is clean but WAIT!

- Look IN the port and make sure you see the Cylinder WALL!!! If the wall of the cylinder is not completely covering the hole, turn the engine over by hand (a little cranking) until the wall of the cylinder completely covers that hole!
- Then, blow it out with compressed air and maybe take a screwdriver to scrape some things but watch it do NOT touch that cylinder wall!

Now, with port clean and muffler off the engine, start it and RUN but ...
well it's kinda loud lol
But, if it runs ok with the muffler off, then your problem is a clogged muffler.
see what that does thou, it eliminates one more possible problem.

[walker/redmax]

Was your mower running low on oil? I know it sounds obvious but one time I had a 20hp that was burning oil and I let it get too low and the second cylinder ceased up. I ended up having to replace the engine. I hope that its not anything as serious as this!:waving:

[TOSLC]

Pugs - Yes the engine is OHC and kinda hard to find parts for. One dealer I went to looking for the coils wanted to argue that the model number was wrong. But it's an engine Kohler builds for Walker. I wasn't that concerned with 20psi difference since they are both over 100 . . . but I'll consult the dealer about maybe a "minimum"? Also I'm not sure what brand the leak down tester was (borrowed from dealer), it just had a gauge that read "Good, Moderate, and Fail". Also not sure where it was going, but I'll do more tonight.

Topsites - I had the muffler off when I put a rag over the exhaust port to see what the pulses felt like. That's when it tried to fire more? And with it being overhead cam and valve I'm not sure I'll be able to see the piston or wall. But I'll look at that as well when I get home.

Walker/Redmax - It could have run low on oil (because it does burn some) but I check it everytime before I use it. I added some before that run. And added some (maybe 2 or 3ozs) before the problem occured, but I don't remember it being an excessive amount (more than usual anyway). Also I know the piston is moving because I checked TDC before the leak check. But it could be scuffed and causing drag?

[pugs]

You might not want to do this yet but before you give up, and you also need to do this during the early afternoon due to noise but...

Seeing how it backfired (through the muffler, yes?), it is possible something came off inside the muffler and is clogging...

So, remove the entire muffler but before you play with it, with the muffler off first inspect the exhaust port to make sure it is clean but WAIT!

- Look IN the port and make sure you see the Cylinder WALL!!! If the wall of the cylinder is not completely covering the hole, turn the engine over by hand (a little cranking) until the wall of the cylinder completely covers that hole!
- Then, blow it out with compressed air and maybe take a screwdriver to scrape some things but watch it do NOT touch that cylinder wall!

Now, with port clean and muffler off the engine, start it and RUN but ...
well it's kinda loud lol
But, if it runs ok with the muffler off, then your problem is a clogged muffler.
see what that does thou, it eliminates one more possible problem.

Ummm...you will never see the cylinder wall. Its a 4 cycle engine. It has something called valves....

Kohler didnt make it just for walker but it just never caught on. They had some issues when they first came out and didnt sell and eventually were just phased out.

Kohler doesnt have a minimum compression. 20psi is a decent difference though.

[tomo]

hello, as i stated not familiar with that engine but , being that it is OHC[over head cam ] does it have mechanical tappet [valve ] clearance ,spec should be available .Tappet may be riding cam [leaves valve slightly open ] Check clearances with feeler guage as per manual either under cam side or valve side .

Second time compression check as i mentioned then 4x squirts of oil in to cylinder and recheck comp .If comp comes up probaly 50 psi or more it is rings ,if it does not it is valves ,not sealing . Maybe due to as i mentioned above .
tomo:waving:

[ducky1]

About the only thing left would be a head gasket maybe?

[Lazer Man]

We had a similar sounding prob on our 26hp Lazer, ended up being a bad cam shaft replaced and all is well. Just a thought as your prob sounds similar.

Bob :waving: :waving: :waving:

[ztrlvr]

Had a Walker MC model year 1999-2000.

It backfired and lost power and one cylinder, don't know which one. Took it to Walker dealer and they diagnosed and fixed it. The problem was a belt that drives the camgear slipped and knocked the timing off. They reset it and it works fine now. Hope this helps if you have not found a solution.


I have a 99 Walker CGHS that has a 16HP VTwin Kohler. About 1700 hours and has run perfectly up to this point. I mowed two weeks ago and brought the mower into the shop hot, shut it off, and it Back fired. No big deal I went into the house not giving it a second thought. Well the next time I go to use it the mower only wants to run on one cylinder. To make a REALLY long story short I'll list what I've done to this point, and hope that someone has some idea's.

Two new Kohler Coils
Two new spark plugs (Swaped them from Cyl to Cyl - no change)
Flywheel Key is fine
Compression Checked (Cyl #1 = 120psi, Cyl #2 = 100psi)
Cylinder Leak Down - Moderate range (good for 1772hrs)
Cranked over engine with valve cover off - Both valve's moving

I'm at a loss here, and could really use some advice before I throw any more $$$ at it. Like I said I think it might of had something to do with the back fire because it ran perfect to that point. It's cylinder #2 that's missing out, and one more thing to add is if I cover the exaust port while it's running, it trys to fire that cylinder more often?

16Hp Vtwin Kohler
Family: TKH574U1G2RA
Model: TH16S
Spec No: 52518
Displ (cc): 520
Serial: 2816000761

[pugs]

Had a Walker MC model year 1999-2000.

It backfired and lost power and one cylinder, don't know which one. Took it to Walker dealer and they diagnosed and fixed it. The problem was a belt that drives the camgear slipped and knocked the timing off. They reset it and it works fine now. Hope this helps if you have not found a solution.


Good call. I forgot they were belt driven OHC...not chain. That many hours...could be time for some new belts. It would also explain the lower compression on the one side since its the valves may be opening and closing out of time.

That is probably gonna require pulling the engine and splitting it open...just to warn you :(

[lucforce]

What has likely occured is dirt has worn the cam gear to a point that the belt is no longer tight. The belt then slipped a few teeth on one cylinder and caused the backfire. Now that cylinder's cam is out of time.

There are no head gaskets on this engine.
You do not have to "split the engine."

Replace the timing belt and the gears. Then adjust the valves.

You do have to pull the engine-Not a big deal.
You do have to get the drive pulley and flywheel off-Can be a bit tedious if you are trying to save the pulley.

[pugs]

What has likely occured is dirt has worn the cam gear to a point that the belt is no longer tight. The belt then slipped a few teeth on one cylinder and caused the backfire. Now that cylinder's cam is out of time.

There are no head gaskets on this engine.
You do not have to "split the engine."

Replace the timing belt and the gears. Then adjust the valves.

You do have to pull the engine-Not a big deal.
You do have to get the drive pulley and flywheel off-Can be a bit tedious if you are trying to save the pulley.

Are the cam gears out in the open? I figured they ran them in the oil like the Honda OHC engines.

That will definitely make things easier.

[TOSLC]

ztrlvr - That's what I thougth might have happened, but I don't have any idea how to time the engine. I'm not sure if the valves are zero clearance (can hit the piston) if they are not zero clearance I'll just change the belt one tooth one way, start it, if not fixed switch two teeth the other way.

pugs - I've already had the engine in and out 3 times working on it. Had the pulley off, flywheel off, valve covers off. So it's no big deal now. I can have it out on the ground in 15 minutes. I'm thinking about working on Walkers for a living now. Ha! Ha!

Thanks again to everyone. This is a great forum to get some advice. Lots of different view points and lots of knowledge!

[tomo]

:waving: hello,
how did u go with your engine ?
It would be highly recomended if u change the cam timing to do it as per manual [timing belt install if so equipped] After install turn motor over by hand to check 4 obvious valve to piston interferance . Recheck timing mark alignment. [belts particularly can jump A TOOTH upon install] Then u can start it up .

tomo

[ericg]

Hello, you have a Kohler Model TH16-52518 which was made to fit a Walker only. If you go to the Kohler link below:
http://www.kohlerplus.com/main_frame.asp
you can open and download the repair manual (TP2480) for this engine. In section 11 (reassembly) it goes into great detail about how to install the timing belt and check the valve adjustments. This should get you back on the road.

[lucforce]

Yes, you should download and read that manual.

The manual though advises using cam holder tool # something. I have never actually ever seen this tool.

Line up the crank gear, and the holes for the tool in the cams will be horizontal as you look at the engine, if your engine is in time.

[ericg]

If you are interested, there is a Kohler cam holding tool on ebay under item4331583512

[TOSLC]

I appreciate the help. I have not had a chance to look at it yet. We had twin boys back in February (plus our 2.5 year old boy) and it requires me to be in the house when I'm not working or working overtime. So I'm a little slow with projects in the shop, but I hope to make it out there in the next night or two.

Also I can't get the manual to download here at work so I'll try it tonight from home and see if it gives the the info I need.

Again I appreciate the help, I really do . . . as I don't really want to pay a dealer to fix it! Give me another night or two and I'll hopefully get some free time. Thanks, John.

[ericg]

Go to this link:
http://www.kohlerplus.com/login.asp
click the box that allows you to enter as a guest
all of the engines will come up grouped by family
click the box for OHC
click the box for the TH16
at the bottom of the page, click the TP-2480 service manual and it will download.
Go to the section labeled reassembly and there you will find all of the steps to reinstall the timing belt.

[TOSLC]

Go it, and I'm printing it as I type. Thanks again for the help.

[TOSLC]

Problem Solved: Cylinder #2 was out of time. It was three teeth off from where it's supposed to be. I took the engine out Saturday night and moved it one tooth, checked for valve clearance, put it all back together and it run better (actually firing again) but not right. Took the engine out and back apart again and Dad showed up by then and after a brief argument as to go one more tooth, or two, I gave in and went two. As usual, Dad was right and it run perfect after that. Welded the muffler (had a crack in it) this morning at work and will hopefully get the chance to mow tonight.

Thanks again so much for everyones help and advice. Special thanks to ericg as I would have NEVER figured out the cam timing without the manual. And honestly can't believe how easy it is to get ahold of Kohler's manuals.

Thanks again I appreciate it, and my wife appreciates not having to pay shop rates! : )

John.

[ericg]

John, I am happy that everything worked out for you. As a newbie to this forum, I find that there are so many people willing to share information and that is waht this forum is all about.

Eric