Hi,

I was wondering if anyone could give me more specs of the Tail Light Bulb (Part No. 26.21-047) used on a 421-048 style tail light. I currently have a single filament bulb. The only time I can make the bulb light up is when I close the hi-beam switch. I am wondering if it is supposed to be a 2-filament bulb. If possible, can you give me a more commercial part number rather than a Bultaco serial number for the proper bulb.

If the part numbers referenced above are not factory part numbers then reference the Bultaco.com website and service manual for details.

Thanks

2 filament bulbs will have two contacts in the socket(add the case for earth), what does yours have? The fact it lights when applying high beam is a bit more disturbing?

The bulb I currently have has one filament thus one contact on the bulb.

As for the light socket, it only has one tab, I believe it is intended for one or two contacts on the bulb, the latter being parallel and both would contact the tab simultaneously. Is that an electrically correct statement?

I must say I am terrible with electrical engineering; I've taken the engineering entry level electrical course 4 times .