Stalling after 45 Min.

[tomtractor 71]

So my WH c125 is stalling after about 45 minutes of mowing. I have changed the gas cap (it is vented just fine) condenser, spark plug, oil, new gas. Is it possible it was over heating? After it cools down it starts fine. What is the problem.

[stevebo-(Moderator) 8,527]

This topic came up before and Sparky had a good suggestion...

While it is still hot and shuts down right away pull the plug and see if you have spark? If not then keep tracing it back until you find the issue. If nothing at the plug then go to the points. If nothing then you may have a faulty stator but I am not sure how to test that without it running? You may need some SOI help here...

[tomtractor 71]

I will give it a try next time I mow. Also what does "SOI" mean?

[stevebo-(Moderator) 8,527]

Save Old Iron who is a member here is tops with electrical problems. ..

[rmaynard 16,289]

This is how to test a stator without the engine running, using an ohm meter. With the engine stopped. remove the stator wires from the regulator. Place the leads from the ohm meter on the wires from the stator. You should read approximately 0.1 to 0.2 ohms. If so the stator is okay. If the meter read infinity the stator is open and needs to be replaced. With the engine stopped place the meter leads on one stator wire and the other meter lead to ground. If the resistance is infinity (no continuity), the stator is good. Do the same with the other wire. If the meter reads a resistance or you have continuity, the stator is shorted and needs to be replaced.

HOWEVER...having described how to test a stator in a non-running engine, the problem is NOT the stator. The charging circuit does not have to be connected for the engine to run. However, the battery has to be charged and connected, so that there is power to the ignition coil.

My feeling is that if you don't have a fuel starvation problem, then you have a coil that is breaking down when it gets hot, or you are losing the electrical connection from the battery to the coil. Rarely does the external wiring break down after running for a period of time, but something internal like the coil, which gets hot will.

[stevebo-(Moderator) 8,527]

You are right Bob the stator is only going to send power to the voltage regulator which in turn will convert the power down from about 35 volts to around 12-14 volts which charges the battery. This should not be an issue as to why the tractor stalls. Bob's thinking the coil is bad may be your issue. Good luck-

[Save Old Iron 1,571]

But on a more serious note, these are always interesting issues - time dependent failures.

Two ways to approach a suspect coil without outright substitution of the coil.

1/ Let the tractor cool down completely. Before attempting a restart, "pre-heat" the coil with a hair dryer. If coil overheating is causing the issue, the tractor may now only run for 5 - 10 minutes before shutting down. This would be some strong evidence the coil (or even the sustituted condensor) is heat sensitive.

Older oil filled coils can loose oil and overheat. Newer epoxy filled coils perform better. If you dismount the old coil, shake it, if the oil sloshes around inside, the coil is suspect.

2/ once the tractor has stalled, try cranking the engine with a spark indicator in line with the spark plug. No spark - then check the igntion circuit. If spark is still present - then suspect a fuel delivery issue.

If no spark is seen, make certain you still have 12 volts to the positive (+) side of the ignition coil. It is possible you are loosing power thru the ignition switch due to corrosion or loose connections on the ignition switch terminal.

If power is seen at the (+) terminal of the coil, take a jumper wire from ground to the coil's negative (-) terminal. With the spark tool still attached to the spark plug, touch and remove the ground wire from the coil (-) terminal. This will simulate the points opening and closing. If you get a strong spark using the jumper wire, your points may be suspect.

[SolarStallion 38]

Hi,

I had a simillar problem with my 312-8. It was my fuel pump going bad. I replaced it and it runs fine again!

[tomtractor 71]

The one thing I find strange is that while the motor is running the clear fuel filter is almost empty. The filter only fills after the tractor has stopped. Although this doesn't change the fact that after the motor has stalled it still doesn't want to start after about 2 minutes. I feel heat is the problem.

[tomtractor 71]

The Oil is sloshing around inside the coil. I am going to go to NAPA today and try to purchase a new one. Any other suggestions for purchasing a new coil.

[rmaynard 16,289]

A Kohler brand coil is part number 41 519 21-S. Your local NAPA auto parts store should carry one with the number 701634.

[squonk 43,714]

Another Napa coil that will work and most likely in stock is Echlin IC 64. Have them see if they have the consumer version of that coil. It used to be IC 64 SB. They have changed their lines so much in the 8 yrs since I left there I'm not sure what the cheaper line code is anymore. It's a universal internally resisted coil.Sold them by the tons to tractor repair shops.

[clyde 5]

id check the point gap when they warm up the gap gets smaller

[tomtractor 71]

So I went to Napa and their coil has oil that sloshes around like mine. The guy there says it sounds like a fuel problem. So now I am questioning the fuel pump. I ask again - While I am running the machine at full speed the fuel filter looks like it is almost empty. Is that normal. If so great. I will test for spark it the machine stalls while I mow in a few minutes. Does anyone know best place to purchase a fuel pump if that is the problem. Also part number. As always thanks very much for any info.

[Marv 979]

I had this problem with my C145. Usually it happened an very hot days. I replaced the fuel pump with an electric pump and it has been good ever since.

Marvin

[tomtractor 71]

Just got in from mowing. I was mowing taller grass. Working the machine. So again after 45 min. the tractor stalled. The tractor started and ran for about 30 seconds before sputtering and stalling. I can do this a few times. It seems like there is a little fuel at the bottom of the gas filter. (Today is hot 85 degrees like last time this happens) Can a fuel pump over heat? If so- is this what happens? So let me know (fuel pump or Coil).

[rmaynard 16,289]

Fuel pumps generally don't over heat and stop working.

My fuel filter always appears near empty when running. If you are not pulling a vacuum in the tank by having a clogged cap vent, you may be getting fuel line collapse. Be sure all fuel lines are routed in such a way that they don't touch hot surfaces or pass near the muffler causing vapor lock.

Next time it stalls, let the engine cool a bit and carefully remove the bolt that holds the bowl onto the bottom of the carburetor. if gas pours out, you are not having a fuel delivery problem, and you can concentrate your efforts on finding why you are losing spark. Best way to test for a heat related bad coil is to replace it with a known working one.

[woodchuckfarmer 333]

How anout the little screen thats built into the shutoff valve in the tank is open or pluged. This just a thought....Wayne

[tomtractor 71]

Awesome. I will check it out Monday. It's funny, usually it bothers me when something doesn't work. This time it's kinda fun problem solving. Thanks everyone. I will first replace one of the fuel lines which is stuck between the throttle cable and the fly wheel cover. Maybe it is collapsing from the heat? Also if it still stalls - I will remove the bowl and see if it is full of fuel. If all that fails I will get a new coil.

[tomtractor 71]

So I installed the new coil napa ic64sb and now the motor doesn't even start. The coil says (does not need a resister) Does this mean I don't need the condenser? It actually started with the old coil. Now what? - Now my wife is unhappy. I am feeling the pressure!

[rmaynard 16,289]

You always need a condenser. That statement "does not need a resistor" means that the resistor is built in. Be sure that you have the 12 volts going to the (+) lug, and the condenser and points connected to the (-) lug. Be sure the condenser body is grounded.

[tomtractor 71]

So I hooked up the old coil and the motor starts. Is it possible the coil (napa ic64sb) is incorrect?

[rmaynard 16,289]

Although the IC64SB was mentioned by another member, the direct cross for the Kohler coil is a 701634.

[horsesaver98 18]

it is the fuel pump if it gets hot the fuel pump will expand and the gasket will come loose and it will suck in air you need to reroute the egsaust and it should be find and run all day

[WH4ME 6]

Had the same thing happen to a c141. Replaced the coil,condenser,points,spark plug and wire,new gas line and filter, pulled and cleanded the gas tank, put in a new gas shut off valve, and a new gas cap. Tractor would run for 45 to 60 minutes then shut off, and not start again untill the engine was cold. Replaced the fuel pump, problem solved, workes great. Wish I tried the fuel pump first,would have saved alot of time and money.