1872 no spark, where to start ?
 

Hi All,
I experianced my first glitch with my 1987 1872 tonight. The tractor did not want to start at first, then did. After starting, the amp gauge was charging then went to zero and then in a little while back to charging. While sitting running, about half throttle it quit running. Has fuel, no spark at plugs. Main fuse is good. printed the magnum 18 manual off of the Kohler web site. My Ohm meter reeds 28.14 between both plug wires, for the secondary test, but how do I perform the primary test? 8.1 I believe. if the coil is bad will I have to remove the engine to replace it?
Thank you in advance,
Mike

I see its an older post but it sounds like you have some sort of short I would think. Maybe at the switch or something?:bigthink: With the amp gauge jump around too makes me think its loosing connection and then regaining connection. Hope you got it figured out by now. :beerchug:

1872
 

Hi All,
Still no spark, Changed module, Stator, and Lead from module to connector. Still no spark. does anyone know where the safety switches are? when I tested the key switch, it tested ok. all the grounds are hooked up. Any suggestions will be appreciated.
Thanks, Mike

Safety switches on my 1872 only stop cranking.

Is it cranking? It is not the safety circuit.

I had almost the exact same problem on my 1811 (X82) and it turned out to be the fuse holder on the lower dash. I went through all of the safety switches FIRST and then noticed that the voltage to the start sw was not reading 12 v but only 6 v. The fuse was good but the ends inside of the holder were getting dirty with age and humidity. I jumped the holder and the engine cranked right up. I am not sure if the amp gage was zero or discharging in my case but I wouldn't think it would be if the circuit was intact. Maybe you will be lucky and this is all the problem is. If not I would expect a bad connection too.

One of the 2072s would always die on my back hill and not restart . Used to drive me crazy as to why it always died in the same spot .

Traced the problem to a cracked ignition housing . Still connected but when going uphill , the wire layed on the other and shorted out . :angry:

On a magneto engine, the battery has nothing to do with the spark. Disconnect the kill wire from the mag to eliminate all of the wiring and stuff (and remove both spark plugs so it cannot start, as you wouldn't be able to stop it if it started) and check for spark. If you don't have spark at this point, it's the magneto. Sometimes they are gapped wrong and give you weak spark; check the air gap and set it to 0.008" if it is greater than that. If that doesn't fix it, it's time for a new magneto. You can get it off without pulling the engine, but it's far easier to pull the engine. The two bottom bolts for the flywheel shroud are really hard to reach when the engine is in the tractor.

It sounds like you also have some other electrical problems, but they are unrelated to this.

1872
 

Thanks All,
I will try again tommorrow, Matt I already had the engine out and replaced the mag with a brand new unit, replaced the lead from the mag too the connector with a brand new kohler unit also put in a used stator that was tested prior too me, and i still have no spark . tonight as suggested by our CC dealer i disconnected the engine to main wiring harness,which he said should elimenate wiring problems, but still no spark.
does anyone feel that the key switch could be bad? I did test it as the kohler manual states and it tested out ok so I thought that wouldn't be it.
It does crank strong. put in a brand new battery as well.

Thanks, Mike

As long as the switch isn't grounding the mag kill wire in any position other than 'off', it should be fine. Not to mention if you tried it with the engine harness disconnected, then the problem is something on the engine and can't be any of the tractor's wiring.

Is the new mag gapped right? (0.008") How are you checking for spark? Are the spark plugs good and gapped properly? Or here's a really dumb question...is the flywheel magnet still a magnet?

MAtt and your CC dealer are right, you have to seperate the systems, the tractor/harness from the eng to find your problem.

The big problem with this is now your bypassing the safety system and we dont do that here!!!!!!!!!!!!!!!

MODS??????????????????


This is what you get when you try to help someone