Kohler CH22 - No Spark

[2MUCHGRASS]

Hello, I have an older Exmark Laser Z with this Kohler CH22 engine that while mowing a few days ago backfired about 3 times then quit completely. The end result is no spark at either plug. Here is what I have done:

Isolated the white kill wire from the engine connector to eliminate the equipment switches. Verified voltage at the red wire to the fuel cut sol / Spark advance module (SAM) in both start and run positions on the key switch. Verified the oil level is ok, and swapped the pressure switch with a known good one. Replaced both plugs. Had the SAM unit checked at a repair shop and is ok, checked the coil/ignition modules: one on the oil filter side checks ok at all test points, the other one has low resistance between terminal 1 and the laminations. The other test points are good.

I have to be missing something here!!! Why would it lose spark at both cylinders? Which wire ( yellow or brown) going from the SAM to the ignition coils is the ground to kill the engine..I take it the SAM is what grounds them out when the key is turned off???

Kohler CH22S, SPEC 66529, S/N 2629508457

Thanks in advance for any help! Sorry so wordy!!

Bob

 

[Kernopelli]

Not sure if it will help but Kohler website has the service/repair manual for the CH series online, it is pretty comprehensive and has helped me out with some issues with my CH 20.

 

[dourobob]

I realize this is an old post but I am having same problem with a Kohler CH22S on a Wheel Horse 522xi tractor.
Did you get your issue resolved? If so, how?