What are the best options for a replacement voltage regulator to replace the stock unit. Pretty sure mine is bad because all bulbs are blown and it looks kind of crispy. It is not available from Yamaha anymore so aftermarket seems the only choice.

Pretty sure that voltage regulators weren't fitted as standard to those bikes. If you're looking at a small item with one red and one white wire, then that is the rectifier. Maybe post a photo or two.

Yamaha did subsequently advise fitting a single wire 6v voltage regulator (see Service Bulletin in the Tech Library) and these are available used (original Yamaha) or new (pattern).

I think that DEET makes a three wire regulator, but I will leave it to him to advise the ins and outs of this.

I did mean rectifier. It does have a red and believe white wire.

New ones available quite cheap on fleabay (part number 315-81970-61).

Probably best to fit a voltage regulator as well.