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Small Engines (Lawn Mowers, etc.)/Riding mower w/B&S won't shut off w/key


QUESTION: When I turn the key switch off the engine keeps running. I replaced the ignition switch and I checked the wire going from the ignition switch to the coil and I don't see any obvious problems with the wire or connections. Could the coil have a problem that would cause it to not shut off spark?

ANSWER: If the wire is dis-connected, yes.

Was the wire from the ignition switch to the coil labeled with  a number or letter.

Did you use a jumper wire and try grounding the wire that connects to the coil to see if the engine shuts off?  The key switch is suppose to do this, ground the coil wire so the spark stops.

Let me know.

---------- FOLLOW-UP ----------

QUESTION: I didn't notice any labeling on the wire. The wire has 2 places that has a type of butt connectors with tabs that lock them together. I pulled the connector apart and hooked a jumper wire to the end that goes to the coil and I grounded the other end and it still didn't shut off. Next I bypassed the original wire by disconnecting it from the coil and running the jumper wire directly from the coil to ground and it still won't shut off.

How many wires are connected to the coil?  If there is just one, most just have one, and it will not shut off if you ground the connection then the coil may be bad.  However, I have never see a coil with this problem.

Are you sure the jumper wire and ground connection are good?  Did you test with a meter?

Did you have to remove the top engine cover to access the ignition module?

Let me know.


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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