D180 ignition issue

[tommyg 152]

So, I parked my D180 in the garage last week after cutting and all was fine. I went to start it this afternoon, and it just cranked and cranked. No spark. Not even a pop. Plugs were wet with gas, so I know it's not firing. I cleaned up every connection I could find to no avail. I moved on to the ignition switch and one by one, removed the wiring and cleaned up the terminals. Still nothing. However, after that process, I noticed that my hour gauge still ticks when the key is off, and the lights come on when I hit the toggle. That never used to happen. When I position the key in the "run" position, no lights and no ticking hour gauge. When I move the key to the "start" position, the hour gauge ticks and the lights come on, which is normal. Still, absolutely no spark. Any thoughts? Can the ignition switch be the issue? The key is stuck inside, so I can't even spray cleaner in there. Can anyone point me to a wiring diagram for that switch? I'm willing to replace it since they seem pretty cheap, but I'd be nervous about making sure the wiring is connected the right way since the switches I've found just have letters, not abbreviations. If it's relevant, I am not running the stock Kohler twin in this machine, rather a 25 hp Kohler Command since the original engine threw a rod several years ago.

[gwest_ca-(File Mod) 11,046]

The original K-series engine had battery ignition.

The Command engine has magneto ignition.

Two different ignition switches. The magneto is self-powered and the ignition wire grounds the magneto to shut it off. Do not allow any battery power to get to the ignition wire. That will release the magic smoke.

If you can identify the ignition wire disconnect it and isolate so it can not ground. You should have spark. Most ignition switches have the ignition terminal identified with a M.

Sure sounds like the ignition switch you have has failed.

This is a very common magneto ignition switch

 

[953 nut 55,292]

1 hour ago, tommyg said:

Kohler Command

This is probably what your electrical system should look like. When the blowed-up K Kohler was replaced by the Command did you do the wiring? Looking at your ignition switch from behind is it like the 103-991 shown in this diagram?

[tommyg 152]

I guess it does. Mine has abbreviations on it like “gnd” and “bat” and “Ign”. Pretty easy to figure out. Regarding the wiring… yes, I connected everything and it was running just fine for probably 4 years. Until this afternoon. There are two ignition coils on the Command and it seems unlikely that both went bad at the same time.

 

[gwest_ca-(File Mod) 11,046]

If your ignition was controlled by a switch with terminals identified as gnd, bat and ign the smoke has already cleared the scene.

If the ignition switch ignition terminal controlled an isolation relay it would protect the ignition coils and work but the relay is not what the tractor originally had.

[953 nut 55,292]

3 hours ago, gwest_ca said:

isolation relay

This thread will show you how the isolation (kill) relay works.

 

[tommyg 152]

19 hours ago, gwest_ca said:

The original K-series engine had battery ignition.

The Command engine has magneto ignition.

Two different ignition switches. The magneto is self-powered and the ignition wire grounds the magneto to shut it off. Do not allow any battery power to get to the ignition wire. That will release the magic smoke.

If you can identify the ignition wire disconnect it and isolate so it can not ground. You should have spark. Most ignition switches have the ignition terminal identified with a M.

Sure sounds like the ignition switch you have has failed.

This is a very common magneto ignition switch

 

I did have the original switch wired successfully with this engine. Instead of going to ground to shut it off, I allowed it to simply close the fuel shut off solenoid. The tractor always ran for a couple seconds after turning the key off, but there was no backfiring which, I was told, was common with this engine. I feel like I have two issues going on here. The spark and the switch. If I can get the switch working as it had been, then I can isolate the problem further. Right now, I'm leaning toward the switch being faulty.

[953 nut 55,292]

4 hours ago, tommyg said:

Right now, I'm leaning toward the switch being faulty

The switch is wrong for your application and should be replaced for safety sake. Turning off the fuel and letting it die won't cut it in an emergency. Do the job right now rather than wishing you had later.

The diagram I gave you in post #3 will do the trick.

[tommyg 152]

I’ve got one ordered. Should be here tomorrow. I’ll report back.

[tommyg 152]

Got the new switch installed. Took my brother and I some thinking and tracing of the wires, but everything functions as it should. Except I still don't have spark. I'm guessing my next step is to pull the engine, remove the flywheel cover and see if there's anything in there that might be grounding out. Whatever it is, it's knocked out spark to both cylinders. Is it possible that both ignition coils went bad simultaneously? Seems unrealistic, but I'm still scratching my head. Anything else to look for?

[gwest_ca-(File Mod) 11,046]

Need this service manual?

 

[tommyg 152]

Can’t hurt. I’ll see what I can find. Thanks!

[tommyg 152]

Update to my spark-less Kohler. Well, it's still spark-less. I've replaced the ignition switch with the correct one. I did not install any sort of kill wire to the switch. I'll worry about that when I actually get a spark. I've replaced both ignition coils. There are no other connections to the coil other than the hi tension lead to the spark plug. Ground is good. I have literally no other options here. It should just work. But it doesn't. I'm going to call a local repair guy tomorrow unless someone else comes up with any other ideas. The engine is pretty much already out. There are no other relays or electronics on this engine that could be faulty. I even checked to see if there was a low oil sentry sensor attached that may be faulty. There is not. Help!

[pfrederi 17,741]

Sorry can't help... the Command series is too "new" for me

[tommyg 152]

I took it to a guy who works on these engines for a living. After explaining all the symptoms and what I've done to try and diagnose and repair, he kind of just stared at it. I'm not sure if his gears were turning or he was as dumbfounded as I was. I'll report back on the findings. I did totally separate the engine from the tractor wiring harness to isolate the problem and still had the same result. Stay tuned.

[tommyg 152]

Final post on this issue. The guy I took it too was scratching his head for a bit. He felt like it had to be the coil(s). Turns out there were 3 different coils made for that engine, I did not purchase the right ones. Fortunately, I was able to send them back. Unfortunately, the spec number on the engine was worn off, so it was a bit of a guessing game. He did a little research and had me pick up two Kohler Command coils at a local ACE hardware store. They were about 4 times what I paid for the first set. Nevertheless, he was able to get it running, but noticed it wasn't running quite right and was overheating. Turns out that at some point, the flywheel on that engine was replaced with the flywheel from a 23 hp Command and the timing was way off. Fortunately, he was able to trade the coils I picked up with new set of coils from a guy who had a new set from a 23 hp engine. That matched. So, It's running fine now. He did say one of the original coils was working. Why I could not get it to at least "pop" is beyond me.

 

Anyways, I'm back in business minus $280 in my pocket. Could have been worse, I guess.