No spark at spark plug. Craftsman with Briggs and Stratton

[Jdemmco]

Good afternoon I am new to the forum. I have a Craftsman riding lawn mower model number 917-274811 with a 42-in deck and a Briggs & Stratton professional series 18.5 horsepower 500cc motor with one spark plug. I had no spark I replaced the magneto with a Briggs & Stratton OEM. With a spark plug tester I get spark from the magneto to the grounded spark plug tester when starting. When I hook the spark plug tester up to the spark plug I do not get any spark when starting. This is with the kill switch connected to the magneto and with it not connected to the magneto. Has anybody experienced this? Thank you in advance

 

[mechanic mark]

https://www.searspartsdirect.com/search?q=917-274811

Did you set coil gap to flywheel to .010, using a business card? Replace spark plug with new plug per manual part # & check gap before installing. Recheck with spark tester & let us know how it goes, thanks, Mark
Champion plug RC12YC Gap .030.

 

[Jdemmco]

Good morning, I gap the coil put a new spark plug gaped to .0300 in. Spark at tester when grounded on block. Weak spark when connected to spark plug.

 

[Jdemmco]

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