# Magneto coil testing?



## Jakebob (Jun 15, 2006)

I have this 12HP Briggs on a Troybilt tractor. M 281707 T 043501 C 91032111. I tried all the things I learned from previous post to get a spark. First I disconnected the lead from the kill switch, no spark. Then I removed the coil and sanded the magnets on the flywheel and the coil arms, and I sanded the underside mounting surface and where the coil attaches. No spark. I'm using a spark plug tester. Then I checked the end of the coil lead where it attaches to the plug. It was very rusty so I scraped it down but still no spark. I removed the flywheel cover and inspected the keyway. This all looks good. I assume that I have a defective coil unless someone out there can tell me what I've missed. The magnets are strong on the flywheel and all connection points are shiney. Thanks for your help.


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## 30yearTech (Sep 14, 2006)

Make sure you have the coil assembly installed right side up, they can be installed upside down and they will not spark.

If it's installed properly and has a good ground, then it's probably time to replace the module/coil assembly.


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## Jakebob (Jun 15, 2006)

Thanks again 30YT, I've been reading all the threads and learning so much useful information. Coil was in the up or correct position. I'll see if I can locate one that fits this engine. Your help is most appreciated.


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## BillM2 (Oct 14, 2007)

I'm having similar problems with my 12hp B&S. I disconnected the black wire (shut off wire) that goes to the magnetron in front of the flywheel and here what happens: I am getting spark to the spark plug wire but not to the plug. But, when I wrap a wire around the base of the spark plug and ground it, I then get a spark to the plug (nice blue spark at the gap). Previously, when the black wire was connected to the magnetron, nothing. What's the problem do you think and what posts were helpful to you.

Thanks much!


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