Small Engines (Lawn Mowers, etc.): Burned Wire/Diode of a Murray Riding Mower, riding lawn mower, fly wheel

Question

My Murray 14 HP riding lawn mower worked fine until I tried to re-start it after refueling. It cranked but could not start. Later I found that the harness from the stator was burned. It is a two-wire harness: red wire with diode was burn and disconnected, the black one was intact.
I re-connected the charred red wire, the engine starts, but Within 10 second a smoke came out from the fly-wheel area. I disconnect it right away. I know a diode is needed to connect the red wire, but what kind of diode should I use? And the major problem is what's the cause of the burning. Please advise. Appreciate your time. Thanks a lot.

Answer
Bo
The diode is used to change the voltage from the stator
the red wire is used for DC output only via the diode the black wire is used for AC output. The  DC out put is for the engine controls and regulators the AC out put is used for the battery charger rectifier. Sound like you shorted the Alternator/ stator out.What you have is a DUAL CIRCUIT ALTERNATOR 14 VOLTS AC MIN @ 3600 RPM, 2-4 AMPS, DC UNREGULATED. You should have it tested.