Coleman powermate generator 3750w wireless-no output already, tried flashing with 12v volt battery, and by rotating chuck on drill. One diode was burnt out, so I replacrd both without any success. Capacitor does't look swollen although parts of the stator winding are darker than others. Any ideas?

Sounds like it could be the circuit board ,check on the back side for any melted solder.
You might try hooking to drills together , run the one plugged into the generator in reverse put the other in forward , and give it heck.
This has worked for me before.make sure you have the trigger down on both of them.
Luck.