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NO spark Briggs 20hp

2730 Views 3 Replies 2 Participants Last post by  Walt 2002
I have a Murray rider model 4257X8A with a briggs 20 hp twin cylinder engine. cranks over but No spark. How do i test the coil and stator? there is a single wire that goes to the coil from the harness. from what i can tell it is the yellow wire that goes through the safty switches. Is there supposed to be power at that wire or is this used to ground out the coil?
thanks in advance.
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"Is there supposed to be power at that wire or is this used to ground out the coil?"

That is the "Kill Wire" and no outside power of any kind should reach it. It shorts the coil to stop the engine. To test your coil, unplug that wire at the coil, IF there is no spark now AND the air gap, space between flywheel and coil laments is correct, then no fire means the coil is bad.

Walt Conner
thanks walt, looks like i have a bad coil.
thanks walt, looks like i have a bad coil.
This is the one Briggs CDI that is prone to failure.

Walt Conner
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