Opposing 18 hp. Coil issues

[Grasstomow]

I have an opposing 18 horse engine that didn't run when I got it. After thorough check there was no spark. Replaced coil and engine started right up. Ran for five minutes, shut it off to completely re-assemble engine. Engine will not start, no spark!!! %#%@$#*$&^$!!!

Thanks for any replies!

 

[Tinkerer200]

You may have a short in the kill wire perhaps where it comes thru the cooling shroud OR you may have a short feeding voltage to the kill wire circuit which will almost immediately ruin the coil. First I would disconnect the kill wire from its' terminal outside the engine and check. No luck, remove the cooling shroud, disconnect the kill wire from the base of the coil and see if there is fire. No, bad coil. One last chance, remove the coil and make sure the mounting surfaces of both the coil and engine block are shinny bright, reinstall making sure coil is right side up and try again.

Walt Conner

 

[Grasstomow]

Thanks for replying Walt. I am thinking the kill wire does no more than grounds the coil shutting off the fire to the plugs. Now if I don't have a live short in the wiring, could it be the ignition giving me a live feed in the kill wire? Mower sat outside in weather for a year or two. Uncovered!

Wilbur

 

[Tinkerer200]

Not sure just what you mean but the tests I sent should help isolate the problem. It is possible a short in the ignition switch is feeding voltage to the coil thru the Kill Wire which will quickly destroy it BUT I would not go replacing parts until you are reasonably certain of what you are doing.

Walt Conner

 

[Grasstomow]

I did your tests Walt and concluded I needed a new coil. So I bought OEM coil, installed without the kill wire connected (unplugged on the outside). Started right up. Checked kill wire from ignition and found no juice in it. Thanks again for replies!

 

[ILENGINE]

I did your tests Walt and concluded I needed a new coil. So I bought OEM coil, installed without the kill wire connected (unplugged on the outside). Started right up. Checked kill wire from ignition and found no juice in it. Thanks again for replies!

The test for faulty key switch is to connect the red lead of the meter to the kill wire and the black wire to the negative post of the battery, and then cycle the key switch through all positions 50 times, and if you even get a glitch of power on the meter it is faulty and has to be replaced. A momentary short of 12v to the module will cook it.