No spark

[Wayne]

If it aint one thing its another. Blizzard comes, Cub with plow loses spark. Driveway drifting over...

How do I test the coil, first of all? Pretend I'm an electrical dummy armed only with an analog meter and little knowledge on how to effectively use it.

[olds45512]

I would first start by making sure your getting power to the coil, touch the black wire to ground and the red wire to the positive post on the coil with the key on, you should be getting around 12v.

[Yosemite Sam]

I can only guess that you're talking about your 108.

Olds is right, make sure you have power to the pos side of the coil when the key is in the "on" position.

Presuming the coil is good, check the neg side of the coil, when the points are open the neg side of the coil should show 12v, when the points are closed the neg side should show zero volts.

The same should be true at the points end of the coil to points wire.

In my experience, when a Kohler K series loses spark all of a sudden, it's either a bad wire (power not getting to the coil or to the points) the points are crudded up, wet, a bug has built a nest in the point box or some similar such thing.

It's also been my experience that when a coil starts to go bad, it usually causes the engine to "cut out" when the coil gets warm as the engine is running.

FWIW, this kind of thing only happens when you need them most.

Good Luck, we're all rooting for you.

[olds45512]

Originally Posted by Yosemite Sam

In my experience, when a Kohler K series loses spark all of a sudden, it's either a bad wire (power not getting to the coil or to the points) the points are crudded up, wet, a bug has built a nest in the point box or some similar such thing.

I agree, any time I have a Kohler that doesn't get spark I always go to the points first and 95% of the time that's the issue. If your getting power to the coil I would try a piece of fine sandpaper between the points to clean them up.

[Wayne]

Yes its my 108 and its a fairly new Stens coil that cut out suddenly when running yesterday. Fortunately I still have the old coil, which was still working when I replaced it cuz it was ancient.

Coil does have 12v getting to it so I guess its on to the points.

[Wayne]

If I'm doing it right, I'm not getting 12v on the negative side of the coil. One lead to the engine, one lead to the negative terminal (and/or the points end of the points wire) with the key on and points open. Nothing. Wires seem good. Pos side still shows 12v.

[RLause]

You either have an open coil our a short to ground on the points side of the coil.

[Wayne]

Open coil? Que?

[Dart1917]

Open coil = bad coil. Disconnect the point wire at the coil and check for 12 volts on the coil terminal. If you have it now then the wire to the points is shorted somewhere between the coil and points. If not, the coil is bad, try your old one.

[Wayne]

Looks like a bad coil then, I'm not getting anything with the points wire disconnected either. Are Stens crappy coils? It can't have more than 20 hours on it. Should be under warranty.