First, Phil: the Honda G65 engine has a built-in 15 Amp alternator inside the flywheel, as an adjunct to the magneto. If it isn't working, I suggest you correct the wiring so it does. Your other wiring sounds irregular as well, but I don't have a wiring diagram for the HD8. Here is the wiring for the engine itself:
[Linked Image]

Here is the Honda-specified wiring for charging the battery, if that is ever necessary once you correct the wiring:
[Linked Image]

The other issue is, it is the wheel-drive belt tensioner that requires attention, not the cutter drive.