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View Full Version : Weak Cylinder on 20hp Kohler


Turfer
08-11-2001, 10:18 AM
I've developed a weak cylinder on my Walker, 20hp kohler (750 hours). I'm burning about 1/2 quart of oil every 5-8 hours and fouling a plug about every 10 hours. I know I need to get it fixed but I just can't find the time. Am I causing further damage by just letting it go until I can get it to the shop ? I do make sure it has enough oil and it's easy to tell when the plug is fouled. I'm using 10w30 mobil synthetic. I wonder if I could help it out by using a slightly heavier oil. I did put a fouler plug in it but it did not respond well. Thanks.

PARKER124
08-11-2001, 10:35 AM
CHECK FOR A BLOWN HEAD GASKET, IF YOU HAVE ACCESS TO A CYLINDER LEAKDOWN GAUGE. OR REMOVE THE HEAD OF THE CONSTANTLY FOULED PLUG. IF THIS IS A "COMMAND" ENGINE THEY RECOMMEND THE USE OF 10W30 OIL ONLY.

John DiMartino
08-11-2001, 03:34 PM
It sounds like a head gasket for sure.Mine did the same thing,check the gas,fill the oil when is blown.

captdevo
08-12-2001, 10:23 AM
I'm burning about 1/2 quart of oil every 5-8 hours and fouling a plug about every 10 hours.

is it smoking bad?

Pull the head and check the gasket, head and block surface, and cylinder walls, if they are scratched or scarred, you're gonna need a rebuild.

The key is to determine what caused this.

Has it overheated?
How long has it been using oil?
Has it misfired?
Ever have water in your fuel?

When you remove the head make sure the block and the head are decked (go over them with a heavy file)

You could keep running it, but you may cause more damage to your engine.

regardless of the oil you use, you have a serious problem that needs attention.


Good luck!!

John DiMartino
08-12-2001, 01:03 PM
Running with blown head gaskets is very bad for the engine,the powerstroke pressure+compression pressure all go right into the crankcase thru the pushrod passage,where every head gasket blows.This pressure froths the oil,and forces excess amounts of crankcase pessure,more than the system was designed for,so the whole engie actually becomes pressurized,making seal leaks,and gasket leaks/blowouts much more likely.It would be much better if it blew out externally,between the exposed cooling fins no pressurizing crankcase,and you would know it blew right away.

EJK2352
08-13-2001, 12:41 AM
Check for blown head gasket for sure. John D. is right on the money. This is a very common problem w/ Kohler Command V-twin engines.:) ;) :) ED

Turfer
08-13-2001, 08:58 AM
Thanks for all your help guys. It's going under the knife next Monday. When this first started, I had just sold my backup walkbehind and was only left with a 21" for backup. Now I've got my GD chariot so I'm not in such a pinch anymore. I'll only have to 21" 4 - 5 lawns if the Walker isn't fixed by week's end. The problem is very deceptive because it runs so good with a new plug. It does smoke a little but not allot. Anyway, it will be ready for fall cleanups in a couple of weeks. Thanks.

LES
08-14-2001, 11:04 PM
I've worked on 8 walkers in the last two months and don't be suprised if it's more than a simple head gasket. 6 out of 8 needed short-blocks that came in with the same problems. Very common with walkers! No love for them in our shop!!!

captdevo
08-15-2001, 10:12 AM
Les,

FYI

Walker doesn't make Kohler engines.

Sounds Like a Kohler problem!

Turfer
08-21-2001, 03:16 PM
I got the call from the dealer today about my Walker. New engine needed ! It's been an expensive month. He said there was too much damage for a rebuild. He really wasn't sure what caused it but said there was allot of debris in the engine. He did mention there was a metal cover missing from the air cleaner which I wasn't aware of. I have cleaned the carburetor a few times and noticed how easy it got dirty and it was very sensitive to wet weather. This cover may have been missing for a while and it just took it's toll. He said a short block would not be advisable because of the amount of bore he would have to take out because of the huge gap between the cylinder and piston and the cylinder wall damage. In hind sight, I probably could have saved this engine if I had taken it in earlier. I just kept the oil filled and kept the plugs clean and ran it for a couple of months and let it smoke. Expensive lesson learned !!! (800 hours)

PARKER124
08-22-2001, 11:42 AM
IN RESPONSE TO YOUR DEALER'S COMMENT ABOUT A SHORT BLOCK NOT BEING ADVISABLE BECAUSE HE WOULD HAVE TO "BORE" IT OUT. SO YOU KNOW, A NEW SHORT BLOCK IS A COMPLETE ENGINE BLOCK LESS HEADS, FLYWHEEL, CARB, INTAKE AND OTHER, RUNNING GEAR. THERE IS NO REASON TO BORE A NEW SHORT BLOCK. HOWEVER IF THE HEADS ARE EXTREMELY WORN FROM DIRT A NEW ENGINE WOULD BE ADVISABLE, OTHERWISE A SHORT BLOCK IS A GOOD FINANCIAL INVESTMENT, PROVIDED YOUR DEALER DOESN'T CHARGE YOU MORE FOR LABOR THAN THE COST OF A COMPLETE ENGINE.
GOOD LUCK WITH THE NEW ENGINE, OR SHORT BLOCK.

Dave
08-22-2001, 09:39 PM
[QUOTE]Originally posted by Turfer
[He said a short block would not be advisable because of the amount of bore he would have to take out because of the huge gap between the cylinder and piston and the cylinder wall damage.
I would get the above clarffied with your dealer .what Parker has said is right,about the shortblock,If your dealer says that is what he has to do ,I would take the machine to someone confident,I also believe that he have said that the old motor has to much wear to be bored.you cannot tell untill it is mic,for what its worth trash it,get a price for a shortblock plus his labor to change all the parts over,then get a price on a new engine,I did a briggs twin
shortblock,briggs gave 4 hours to do the job if I remember right ,by the time I was done for another 100-150 he could of had a new engine with a 2year guarentee instead of ninty day.All this goin on here about kohler should be put in the forum kohler vs kaw

flipflopman
08-27-2001, 06:51 PM
Hi,

We had a similar problem with our Onan 18 hp. One cylinder had a slight blow by. Enough that it used up 1/2 quart in about 5 hrs. It too ran fine and did not misfire. What we did was rebuild it by inserting a new sleeve, and piston on the bad cylinder and a just a new piston on the good cylinder, along with new set of gaskets. I would suggest you take your engine to a machine shop and have them machine your block and insert a sleeve into it. Our onan is going strong after the rebuild with no signs of any problems. And of course, no more smoke and adding oil necessary..... We paid 400 dollars for this.

EJK2352
08-28-2001, 12:40 AM
Turfer,
Sounds like your dealer is blowing some big time smoke or doesn't know much about what he's doing. I'd consider replacing that engine with a complete NEW engine. You get a 2 year warranty on a new engine vs. a 90 day warranty on a short block. You also get new cylinder heads,carburetor,ignition, etc. etc.. If you go the short block route, be sure the dealer checks out the cylinder heads i.e.(valves, guides, seats, warpage) and does a valve job. Also if you get a new engine you can keep the old one for spare parts.:) ;) :) ED

Turfer
08-28-2001, 08:20 AM
I did put a new engine in my Walker. I went in the shop and talked to the mechanic that worked on my machine. He said there was allot of debris in my engine that probably caused the problem. He showed me a piece on the new engine that was missing on my old engine. It was the metal plate covering the air filter under the air filter cover. It definitely was not there because I removed and cleaned the carb twice plus replacing the filter and cleaning it numerous times and I never saw it. He said they could have short blocked it but the guarantee was only 90 days. With the amount of sludge in my engine, he said I would be taking a real chance. The breakdown on the pricing was another new engine sale for me. Short blocking would have only been a few hundred dollars cheaper and like you said, I get a 2 year warranty with the new engine. I'm satisfied with the results and the dealer has been real honest about all the business I have done with him. The Walker may move back to the number 1 slot ahead of my GD chariot because it drives so different with the new power. Thanks for all your help.