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View Full Version : B & S 16.5HP LT mower with no spark.


soccernut43
Apr 3, 2011, 01:37 PM
I have a Yard Machine rider mower with a Briggs and Stratton 16.5HP two cylinder with opposing cylinders. It seems to have a newer style ignition coil with everything contained in the coil. I get no spark. I don't get 12 volts on the black wire that feeds the ignition coil, not sure if I should. I tried running 12 volts straight to the coil wire and that was not a good idea as the fuse blew. People have talked about a kill switch and I was wondering if that is the plug that runs under the flywheel and cover assembly (black and white wire. The female end of plug has something under the shrink tubing, not sure what it is). Any ideas? Thanks!

jsfocke
Apr 3, 2011, 03:38 PM
The wire that goes to the coil is a ground wire. It grounds out the coil to stop the spark. There should be no current (positive or negative) going to it when the engine is supposed to be running. If you unplug the coil it should run. If it is grounded then one of your safety switches may be keeping it from running. Of course, if you put 12 volts to the coil you may have fried it.

soccernut43
Apr 3, 2011, 05:27 PM
Thanks! I think it may be bad to begin with. Supposed to have internal circuitry to replace old points. I'm going to replace the coil and see if that fixes it. So you are saying just the magnet on the flywheel creating and collapsing the field to create the spark is all that should be happening. Once the engine starts it becomes self sustaining until you ground out coil to stop the spark. Thank you.

jsfocke
Apr 11, 2011, 07:32 AM
Thanks!! I think it may be bad to begin with. Supposed to have internal circuitry to replace old points. I'm going to replace the coil and see if that fixes it. So you are saying just the magnet on the flywheel creating and collapsing the field to create the spark is all that should be happening. Once the engine starts it becomes self sustaining until you ground out coil to stop the spark. Thank you.

That's right.