Small Engines (Lawn Mowers, etc.)/Tecumseh - no spark


I have a yardman chipper/shredder 8hp Tecumseh HM80-15548-IN with weak spark. So far I've replaced the SS module, spark plug, cleaned the magnet and gapped to .012". The wire for the kill switch is OK (not grounded). Can a weak magnet cause a weak spark?????

In theory, yes a weak magnet could cause weak spark but I have never seen this in real world applications.  Too slow of RPM is more likely to cause weak spark but again I've never seen this.

What or why do you believe you have weak spark?  Are you using an inline spark tester with a 0.166 air gap to assist in determining the spark produced by the ignition model?  Have you had the ignition model tested with an Imrie ignition tester to determine the voltage the ignition module is producing?  The URLs below have information on the Imrie test tool.

Let me know why you believe you have weak spark.

Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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