Modern Vespa

I thought I would create a new post for this little task since it was kind of a fun. My 1959 VBA speedometer did not have a light bulb. It just had this empty slot and I had no idea how the original bulb was mounted.

Voodoo gave this this old crusty speedo (at least what was left of it) that had a bulb. Original? Who knows, but I was going to find out what was behind door number one.

So this was interesting. The speedo was lit by 2 of the smallest incandescent bulbs I've ever seen.

I really couldn't use any of the pieces from Voodoo's speedometer, but it did give me some ideas on lighting my own. A bit of searching showed that these bulbs had an E5 base (5mm) and I found some E5 bulb holders and E5 base 6V bulbs. A scrap of sheet metal, a drill, tin snips, needle nose pliers, length of wire, soldering iron and 30 minutes later, I had a replacement bulb holder for my clamshell speedo.

And it works!

Nice and clean

wow illuminates better than original nice job

Be aware of two bulbs overheating and melting something. One is probably enough. It looks a bit to bright to me. Piaggio always had good reasons for what they designed.

Yeah, good point about the heat. Two bulbs definitely work better as it spreads out the light better. According the VBA owners manual, the original speedo bulb is supposd to be 0.6W. The bulbs I'm using are 1.2W each and I've got some 0.24W bulbs to try. Also, these bulb holders came with LED bulbs, but they're 12-14V so they're a little dim at 6v. I'll play around with this to see whats the best combo of heat and light. The best part of having actual bulb bases is that I can easily swap out the bulbs.

Last edited by flyngti on Thu Nov 19, 2020 1:04 pm; edited 1 time in total

Nice work Flyngti!

Instead of two bulbs, you may be able to fit in a layer of something to diffuse the light to reduce or eliminate hotspots. Depending on heat, some typing paper or rice paper might do the job. Maybe a thin sheet of frosted acrylic.

I had to do something similar with my GS 150 vs4 speedo, which had the same kind of slot on the side. Mine took a single festoon bulb however. I used an old fuse holder mounted on a thick bakelite base that just barely fit into the slot to hold the bulb inside. I had to grind down the base quite a bit to make it thin enough to allow for installing in the head slot. Seems to work well, and is very solidly soldered in place, but I haven't tested it. Not sure how to yet.


The bulb holder looks to be some kind of wood now that I look at it. Perhaps Lignum Vitae? Don't remember where it came from.

Do you know the wattage on that festoon bulb? I had considered doing the same thing you did, but I was not able to find a festoon bulb of low enough wattage. Also, I didn't want to do too much cutting and grinding on my original speedo to make the festoon bulb and holder fit. I tried 2 0.24W bulbs, but it was too dim. I think the 2 1.2W bulbs was too bright so I ended up just using a single 1.2W E5 base bulb. I put some aluminum tape on the lower half of the white plastic piece to block and reflect the light to the top half where it's needed. To me, this was the best solution.

I like your finished product, good work there

Thanks! This was a fun little side project

The wiring diagram I got for my vs4 from scooterhelp says 1.5 a , which is the same for the pilot light. I don't know how bright it is yet because I don't want to charge the battery before getting the correct ignition coil.

Do you mean 1.5W and not 1.5A? Is your bike 6 or 12V? I'm assuming you have a new battery and have not put acid in it yet. If you're just looking for 6V source to test the light, use 4 D cell batteries (or any size, really) to get to 6V. Even easier if 12V since you can use any car battery or find a common 12v wall wart. As I mentioned, I had a really hard time finding a low wattage festoon bulb and I think anything above 1.5W would be way too bright.

Sorry I meant W. I always get those mixed up for some reason. My scooter is a 6 v system and I have a new battery that I haven't charged yet because I'm waiting for the tooth fairy to provide some money to get the right ignition coil. I'm sure I have other problems too, but I won't discover those until I get her started up I think.

I have a thread going like yours under GS 150 restoration. I'm also a newbie.


just made my own spare tire holder.