Kohler engine problems - craftsman lawn tractor

A failing coil or ignition module can act up when motor gets hot, see if there is spark just after it dies.

I had a similar problem with an old (1969) Wheel Horse. There was dirt in the gas line that would settle and then rise after the engine had run for while. It would clog the float valve in the carburetor. Drain the tank and clean the line. __________________ Bill Waller New Eagle, PA

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Ditto - same problem & same fix. There was a screen filter at the end of the fuel pickup tube in the fuel tank. Varnish sediment would be picked up to the screen stopping the fuel flow. When the engine died the sediment would settle back into the tank. Then recycle.

KC

Better replace that battery, your probably cooking you charging circuit, with it trying to charge your bad battery,false economy. Don't know the charging circuit, but maybe its stealing the current to make ignition system operate. It probably the fuel system.

Visit Harbor Freight and pick up their version of the battery tender for about $5 when it's on sale. I've been using one on my John Deere lawn tractor since I bought it new four years ago. I'm still on the original battery and it starts easily every time.

It will not overcharge the battery like a common charger. I just hook it up to external terminals I rigged up to make it less of a PITA. It stays hooked up any time it's not actually being used to cut grass.

Mortimer Schnerd, RN mschnerd at carolina.rr.com

. =EF=BF=BDThis

se advise, Thanks.

I doubt it has anything to do with fuel delivery. I would look at the safety switches first. They get dirty, ground out, and they also wear out.

To check them: There should be one wire coming from the motors coil, then it splits into different areas that go to the different switches. If you disconnect the main wire, that will disable all the safety switches. Then run it to see if the problem still exists. If it does, then it is NOT the safety switches.

Diagnosing the problem will take a systematic approach. Rule-out each system until you find the system (fuel, electrical, compression and etc.) that is faulty.

Hank

That does make sense. I was thinking more of smaller engines I've serviced. Bad quality motor oil will cause problems. Also, an ignition coil going bad. But, the crud in the fuel tank makes sense.

Wonder if you can take the tank off. Leave about half full. Plug the fuel outlet wtih a finger, shake the fuel around to suspend any particles. Pour the fuel into a coffee filter and strainer over a can of some kind. Strain all the particles out. Put the now-clean fuel back in.

The question is why after 20 minutes, safteys should be almost immediate, fuel should be an issue within maybe 5 minutes as thats about the max for a float bowl to hold and the choke is not needed, unless its not venting the tank so as to not feed fuel. My Lawnboy did this one year, first it would not restart hot, following year it died after getting hot, the following year it would not start at all, it was the ignition module, Once I bought a used boat motor, no wonder the guy selling it only gave me a 5 minute test ride, after 15 minutes one cilinder would stop firing, only an expensive new ignition module fixed it. Coils going bad can also fail when fully heated up. I think a first test is a spark strength and color check just after it dies, and when cold. My lawnboy still sparked, but this test is faulty since under compression and with fuel in the cilinder it takes much more voltage than in open air. Another indicator ive noticed on several small motors, and my car, with failing ignition components is ok idle, and rough running under load.

Well, it could be any of the systems. Disconnecting the ground wire is eliminating one potential problem within 1 minute. By isolating different systems, you can rule-out those systems. Ground wires come loose, get worn, switches wear out and etc.

No matter what, it will take time, effort and a systematic approach to diagnose his problem. The Gas cap vent is a good start too. Quick and easy.

Hank

Hustlin' Hank wrote: ...

Of course it _could_, but one might as well start w/ those that have some semblance of a resemblance to being at all likely to cause the observed symptoms. The likely safety interlock system failure modes don't match at all well...

Gas tank venting is, otoh, worth checking in the short/initial list...

--

Again, all systems have to be ruled-out. If you take just one system at a time, it would take forever since the OP stated it would run fine for 20 minutes. IF he can rule-out more than one system at a time, his diagnosis time will be MUCH less. As I stated earlier, the gas tank venting is a good idea, but may not be the problem, nor the grounding systems, BUT, they are 2 points that should be checked, are easily checked and ruled out at the same time.

Hank

hillclimber had written this in response to

:

Thanks for all the advise and help. I have installed a new battery (from Tractor Supply Company - good prices - better that Sears!), fuel filter, spark plug (old one looked pretty bad), cleaned out the fuel tank, checked the fuel tank cap for air flow. It starts good and runs good. Mowed for a hour or so with only a small problem. I have some fairly good slopes in my yard (I live in mid-Tennessee) and when going up a slope of 5 to 10 degrees the engine will sometimes try to stall. I can turn sideways on the hill and it is OK. This used to only occur when the gas tank was getting very low but now occurs with a full tank. I know the gas is gravity fed but it does not look like the tank is below the carb. on the engine - Any comments? Thanks.

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Is the engine equipped with an oil sensor? It is designed to kill the engine when it is not happy. Kohlers are sensitive to starving a crank bearing if run on hills long enough to oil starve the bearing.

hillclimber had written this in response to

: Do not think so. In looking at the engine parts pictures & parts list (oil pan/lubrication section) there is not a sensor shown. The engine does have a oil pump as it is a pressurized oil system. I did double check the oil level and it was right at or a shade above full. Any comments? Thanks.

------------------------------------- DanG wrote:

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You didn't say whether you checked any of the wiring as I suggested earlier. Did you?

Hank

cjsinko had written this in response to

: I have the same mower and had the same problem. tried every possible solution. Seemed like an electrical problem. Gave up had sears come out and the problem was water in the fuel bowl. Does it stall under power, i.e., when the blades are engaged and you are mowing? As it stalls try disengaging the blades does it continue to run? If so I bet it is water.

------------------------------------- hillclimber wrote:

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hillclimber had written this in response to

:

------------------------------------- Think I found out the problem - looking at the fuel tank and the carb. - they are almost level and on a hill the tank is lower than the carb. so.... I am going to try to put some shims (about 1 1/2 inch) under the fuel tank (there is room) and see if that helps.

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hillclimber had written this in response to

:

------------------------------------- Think I found out the problem - looking at the fuel tank and the carb. - they are almost level and on a hill the tank is lower than the carb. so.... I am going to try to put some shims (about 1 1/2 inch) under the fuel tank (there is room) and see if that helps.

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hillclimber had written this in response to

:

------------------------------------- Think I found out the problem - looking at the fuel tank and the carb. - they are almost level and on a hill the tank is lower than the carb. so.... I am going to try to put some shims (about 1 1/2 inch) under the fuel tank (there is room) and see if that helps.

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