Briggs and stratton engine

Hi. Have a b/s engine. It runs very well with ground side to armature disconnected but won't start with wire connected. Armature was bad, put new one with same results, changed ignition switch because connectors were loose got same results. Checked seat switch its good. Can I install a cutoff switch to ground side on armature without damaging any other parts? All wiring look okay hate to change harness everything else works good. Any help of advise will be greatly appreciated. Thanks

You're not giving us a clear idea of what you are trying to explain, what are you calling the armature, and the wire you are connecting/ disconnecting, ( starter ..?? / solenoid ) can you post a few pics so we can see what your talking about, ALSO please include your mowers numbers, (mower and engine) see example.....

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https://www.youtube.com/watch?v=pJse_XQrO4Y

Hi Boobala. By armature i mean the ignition module(magneto) that makes the spark for plug. It has a single ground wire. Mower starts with this wire disconnected. Will not start with it attached to magneto. Starter works fine, solenoid also works engine does turnover
Mower murra y 40 in deck
Model 405000x8f
Manufacture have it for 12 years
B/S engine
13.5 no
Model 21B807
Type 0296E
Code 041119as. May not be totally correct. Hard to read

Lenny, that black wire to the coil is the ground wire to kill the engine, it is wired through the safety switch's back to the ignition sw. that's what stops your engine when you turn the key off, it also grounds out the coil, if a safety switch is not in the correct position, it also has to be connected to the ground terminal of the ignition sw. I suggest you check your safety switch's and be sure you replaced the ignition switch with the correct model number, ( p/n 1001993.. shown on the wiring diagram,) the back of the ignition sw. should have letters denoting each terminal so you can check that against the wiring diagram, I also enclosed a you-tube video on how to check your safety switch's ........ trace out your wires with the diagram and we'll go from there...

View attachment 36342

https://www.youtube.com/watch?v=Xi3p465MN1E

Lenny261. Hi checked seat switch its ok. Checked pto switch its ok. Replaced ignition switch its ok. Cut lawn with ground wire to coil disconnected everything good and ok.took switches to mower repair place and they checked them for me. If I bring mower to repair place they will diagnose it for $20.00 . Think I might do that,less stress and trouble. Want to thank you for your help.