I have a 25 HP Kohler on a lawn tractor. It has 2 Cylinders, one of which works fine. I am getting no spark on one of the plugs. I have replaced the ignition module and plug, and am now baffled as to why side sparks fine and the other does not. I used the same plug to test, so definitely not that.. what else could it be?
Jb

Hi,
Does this unit use a SmartSpark module(a black plastic box approxiamately 2 1/2" x 3 1/2") bolted to the engine? This could be the problem, if there. Dealers often have the diagnostic tool to test this. Also, there are sometimes diodes in the ignition ground wires between the modules beneath the shroud. A bad diode could be it. Diodes will be present with the SmartSpark and sometimes without. Removing the shroud and unplugging the ground wires will test that(it just cannot be shut down. One other tiny thing, did you mount the new module upside down?
Peace,
Clarke