What are Some Causes of engine Not Shutting Off.

LarryJohnson

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Occasionally, me mower won't shut off with the key. When it does this, it comes close, but won't completely turn off with the key. I just turn the key back on, then off, and it shuts down. The kill wire on the coil is attached and isn't rusted. The main wiring harness and starter solenoid were new last year. Is it typically an electrical issue or an engine/carb issue? Mower model is in my signature. Thanks
 

EngineMan

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Check the key switch and the ground wire from the key switch. when you turn the key on and then off again and it stops tell me that the key switch is bad.
 

bertsmobile1

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Only one cause, the magneto is not being grounded.
Can be the switch or the ground connection to the switch
The circuit diagram is available here
https://polr.partstree.com/v1/iplimage.php?ir=YToyOntzOjk6ImltYWdlUGF0aCI7czozMjoiYlhWeWNtRjVMMmx0WVdkbGMxdzNOMXcwTTF3d01ERTEiO3M6Nzoib3B0aW9ucyI7YToxOntzOjU6IndpZHRoIjtpOjEwMDA7fX0

Unfortunately one of the down sides of computes is blithering idiots with less than no Ideal of what they are doing can get an application that makes circuit diagrams so the accountants that are destroying most companies and the countries they operate in commission the blind receptionists to make the wiring diagrams rather than pay an electrician to do the job properly thus you gets pigs breakfasts like the diagram above.

You need to back test the M terminal on the ignition switch to make sure it goes to ground when the switch is turned off.
If not check that the G terminal is in fact grounded all the time.
The letters are cast into the back of the switch but you can usually work them out by the colours & positions of the plug.
 

grumpyoldman77

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Solenoid on the carburetor shuts down Briggs & Stratton on V-Twin, Sometimes the plunger
does not seat. Had same problem
 

bertsmobile1

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Solenoid on the carburetor shuts down Briggs & Stratton on V-Twin, Sometimes the plunger
does not seat. Had same problem

While it does have that effect it is not intentional.
The lack of spark is what is supposed to stop the engine.
The solenoid is there to prevent unburned fuel passing throuhgh the engine during run down.
 
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