M18 no spark
 

I'm having an issue with the M18. It was running fine. I let it sit for a couple months and went to start it and the starter wouldn't engage. I figured it was a bad starter. Pulled the side panel off and saw paper towels had jammed the starter onto the flywheel.A mouse had began building a nest in there so I Cleaned that out and the starter worked perfect. Good right? Well then the engine wouldn't fire so checked and there's no spark. I pulled the motor and removed the covers, I was hoping he had chewed a wire but he didn't. So I cleaned what was left of the new nest. So Im at a loss what to check and how. Any suggestions would be appreciated. The nest was new so no urine or dropping's.

This M18 is installed in what tractor? Knowing this could help with diagnosis if we could consult the wiring diagram.

Spin the engine over with the starter while it on the work the bench, with the spark plugs out.
Make sure the kill wire lug on the magneto coil is not grounded ( the one that the white wire attaches to.)
You should have spark, at the plugs laying on the heads, with the plug wires attached to them.
if not your magneto coil is bad.:bigthink:

Thanks, I'll try that tonight.

This motor is on a custom build but if I remember correctly I used an 1811 wiring harness.

Since it is on the bench, there will not be any wires attached to it to worry about.
Other than your jumper cables:
Negative ground to anywhere convent on the block, and touching the positive jumper cable to the starter lug to spin the starter
Of course the plug wires attached to the plugs to check for spark, and make sure the spark plug metal hex is laying on something metal of the block/head/cylinder.
Sorry if his seems elementary/common sense but we have no way to know your knowledge/abilities. :bigthink:

I finally had time last night to check this. There is no spark. I reset the air gap on the coil to make sure it was in spec. So how do I know if the coil is bad or the stator? Also are the cheap chinese coils that are only $20 - $30 any good or do I need to drop $100+ for an oem one?

If you have the funds, I would get an OEM. You might get a good aftermarket and you might not. It is a crap shoot.:biggrin2:

Below is a thread from a friend. By the way he named the Cub Cadet, Skippy.

https://www.onlycubcadets.net/forum/...ad.php?t=50889

Wow that was quite the journey! I'll buy an OEM coil fpr sure. Thanks for that thread. I did pull the plugs and cleaned them. I did notice one was black and the other brown. Is this what he was talking about with his by one being darker than the other?

I think so.