I have a Briggs 22hp (model 407777) on a Troy-Bilt (MTD) frame.. it's about 5 years old.

I recently had a problem with a bad battery which, when replaced everything worked fine.. for about a month. Then the solenoid stuck ON causing the starter to "click" every time the key was turned on. The battery has to be removed on this model to gain access to the solenoid (under the seat), which was removed and a new solenoid installed.. but one wire was not returned to the proper place, a green one that should have gone to the battery ground was instead connected to the open battery terminal on the solenoid. When the key was turned on and the starter engaged, smoke came from the "Y" in the wires going to the lugs on the 2 coils. It appears there was a fuseable link or a diode at the "Y".. not having a wiring diagram, I soldered the 3 leads together. Though everything appears to work, I get no spark at the plugs.

Any help getting this thing going will be much appreciated as I have 3 acres of knee high grass that needs a "trim"...

Found the problem.

Because I soldered the wires together that go to the coils (kill switch circuit), it didn't matter which cyl was firing 'cause the other coil was providing the ground (kill signal) so they never fired. When I removed the kill wires, the engine started and ran fine.

Evidently there were diodes inline that prevented the "cross kill" from happening. Now, I need to find a p/n for the diodes...