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View Full Version : Kohler 12.5 no spark, tried 3 coils, ugh


shopteacher
07-27-2008, 02:54 AM
Hey guys, what's up?
I have a Kohler cv 12.5 and it has no spark. It was running and mowing within the last day. I tried another used coil, still no spark, Then I tried a third used coil, still no spark.

When I put the used coils back on their original engines, they have spark. What gives?

I disconnected the ground wire from the coil to eliminate all wiring problem possibilities. I also got a faint spark a couple of times.

I would consider myself a decent mechanic, so I don't think I am overlooking anything, but why would an engine not have spark with a good coil. I even tried 2 different flywheels.

The magnet on the flywheel is still magnetic, and I know I am cranking her at at least 55o rpm. Any thoughts?????????????

Partsangel
07-27-2008, 11:11 AM
I understand your plight, I had a Tecumseh HH just put me threw the ringer! and as always it turns out to be something simple I over looked :hammerhead: anyway about your coils that work on one engine but not another? well its very possible that the posts where the coil fits on the engine your trying to fix have a little bit of rust on them. Try using a wire brush on the posts and the coil where they meet and brush the Sh (well you know what I mean) out of those areas and retry with out connecting the kill wire. I would also double check and make sure your not putting the coil upside down and also most electronic coils wont fire unless the engine is turning at least 700 rpms.

I hope this helps.
Mike

kawasaki1
07-27-2008, 11:14 AM
what he said.^

sawman65
07-27-2008, 12:08 PM
do you have a spark advance module on you unit? need model # to help

shopteacher
07-27-2008, 04:18 PM
This model does have a regulator on it, but if I disconect the wire so it is just the coil, there should be a spark.

I have filed and thouroughly cleaned all surfaces and have double, triple, quadrupe checked everything.

This is becoming a quest that I cannot let die. I must know why this engine will not produce a spark.

The only thing I can figure is the flywheel, which is not the original one, is somehow bad

Help, save a man from a slow agonizing frustration state of mind. The next thing you will see from me is an inability to type and spel corekly.

Phil G
07-27-2008, 04:53 PM
[QUOTE=shopteacher;2438274]

The only thing I can figure is the flywheel, which is not the original one, is somehow bad

QUOTE]



Has the engine ever run with this 'wrong' flywheel on it?
Do you have the original one that came off it? If you do check the key way and magnet positions match exactly. Maybe the recent coil you've got is not compatible to the replacement fly wheel, just a thought
Good luck Phil :)

Partsangel
07-27-2008, 08:54 PM
sawman65
do you have a spark advance module on you unit? need model # to help

This model does have a regulator on it, but if I disconect the wire so it is just the coil, there should be a spark.

No,
If your engine has a spark advance module on it they have to be connected in order to receive a spark, like sawman65 said....
we need your Model and Spec numbers to really help you...And We Want To Help You....Promise.

Mike

shopteacher
07-28-2008, 01:05 PM
Found the problem. The coil (ignition module) was upside down.

The motor I took the coil from had it that way so I just installed it the same way.
I learned from the experience which is all that counts.

Thanks for your help and attempt at straightening out one guy's ignorance.

I speak softly, but carry a big set of tools.

Phil G
07-28-2008, 03:58 PM
Found the problem. The coil (ignition module) was upside down.



D'oh. Well done for persevering. Don't it feel good to have a result after all that trouble?
atb Phil

http://i55.photobucket.com/albums/g144/PhilGz/raspberry.gif