Modern Vespa

What's the ID on the basket...is it close to 96mm? It's probably the correct clutch that came in a 125.

Yeah close to 96. Since it's so trashed, the whole unit will be replaced. Should I go with the same or move to the larger 7 spring version? It will be built as a stock 150.

Yeah, will do. I don't have any Red Bull, but I do have some hard kombucha .

LOL! Be careful using a kombucha can. It might cause your scooter to start talking incessantly about how it now only drinks artisanal, sustainably-sourced, certified organic gasoline and 2T oil and only want to start if you tell it you're riding to yoga class or Whole Foods.

This scooter and I will get along real well then!

And what's the deal with these fork covers, I've ordered 2 for px. My old one at left and the new non-fitting type at right.

In other news there are various rattles to chase, the cowl signals don't work (one pin is not getting signal, the other side is), the speedo needs a bit of help from speedo king (random jumping at times), but the important stuff works and I now deem it fit for use.

Nearly all P range Vespas and variants (Cosa, PK, most LML) use a simple AC system for the indicators.

Simple version

The current generated by the flywheel/stator goes to the regulator, and then on to the indicator relay. From there it is sent down two wires, one carrying current to power the rear indicators, the other the front. When the two wires reach the handlebar switch each is split, giving four wires in total, and these run to the indicators.

That's simple enough to visualise - One to two to four, with the two taking it in turns to carry the current as it gets switched by the relay. This explains why Vespa indicators flash alternately rather than together, ensuring that there is a constant 21w load on the system, rather than 0W-42W-0W-42W..

Slightly more descriptive version

The power for the indicators comes from the regulator, a silver, ribbed, hexagonal device located under the left hand panel and behind the spare wheel (and battery if fitted). If you examine this, you'll find a wire running to the small square (often green) block sitting in the same area. This is the indicator relay.

The relay has three connectors, and the wire from the regulator runs to the most central pin. A simple description of how the relay works is to imagine a pendulum inside, swinging from side to side and contacting the two remaining pins in turn.
These other two pins have wires which run up the frame to the indicator switch. From here, the current is directed by the switch to the four wires which run to the indicator bulbs.

Fault finding

Because of the simplicity of the system, fault finding is pretty simple.

If all the indicators are out, then the chances are that the wire between regulator and relay has become broken or dislodged. Check and plug back in/replace as needed.

If both indicators at one end have failed, then check the wires between the relay and the switch. You may need to do a continuity test to do this properly (See end). 90% of problems like this are on this part of the circuit.

If both indicators on one side have failed. This is very rare, and I've only ever known it being down to a damaged switch, generally with the wiring being pulled tight and pulling away.

If only one is out, then the problem will be somewhere between switch and earth.

Simple as that!


All that said, there are a few predictable and regular problems.

Firstly, if you get any problems, always check the bulbs. I know it sounds obvious, but the frequency in which you see people chasing all sorts of issues for a blown bulb...
Next are the panels - the connectors at the front can get filled with gunk, making for a poor connection, and the earthing connection through the spring on the top can get similarly affected. Keep them clean and a lot of problems can be avoided.
Finally, front indicator wires are very vulnerable. Any problems at the front, check the two wires that attach to each bulb, these are easily dislodged.


Continuity testing
The easiest way to check for broken wiring is a continuity test: Grab a cheap electrical meter and set to resistance (ohms - the little picture that looks like a bridge!) and touch one probe to each end of the wire you need to test. Hopefully the reading will be zero ohm, or near enough. Anything higher than a small amount suggests that there is an issue with a broken wire.

Today's fun - degunk and start to tear down the 2 port engine that might be the engine for the VBB. It's a Bajaj of unknown vintage - anyone have a source for making any sense of Bajaj engine numbers?

Surprise #1 - no nut on the christmas tree - hmm, that's weird. Hopefully pilfered while sitting around Greasy's shop for some other engine's needs.

Surprise #2 - flywheel has no circlip for removal. Did some digging in my smallframe box of parts and found one that fits. As soon as you try to back the nut against it, though, it just pushes out of the groove. Looks like I'm going to need a 2 jaw puller to get the flywheel off.

Surprise #3 - I had been hoping this engine would be clean inside, as it turns easily. Finding one of the engines as a seals and bearings only job would be awesome. Alas, not gonna happen. Piston has a minor scuff opposite the exhaust port. The bore can probably clean up with a hone, maybe the piston can be made to work. I can't get the crank out yet but I see signs the crank may have kissed the rotary pad based on some scuff marks on the crank outer surface. Also the other web has signs of debris ingestion - maybe a screw at some point.

I'll keep at it. This might still be the VBB engine though, it probably has no real market value, so it seems like the right job for it rather than just occupying room in my garage.

I'd need 2 fresh ones to get it, but I don't think I have them currently. I did think of it. I will search my spares box again.

I found 3 new ones in my stash. So tight I had to battle for 20 minutes to get it in and the blood sacrifice was used. But the flywheel popped off 😎

Can these points stators be rewired to do 12v ac like the double yellow ones can?

For the DIY guys:
1 You need 2 6V stators.
2 Each stator has 3 coils: an ignition coil next to the points and 2 lighting coils.
3 Sometimes the ignition coil is connected to one lighting coil with a yellow wire. Cut the wire and ground the wire coming from the ignition coil
4 Remove that lighting coil (the one with the thick windings).
5 From the second stator, remove the lighting coil with the thin windings. It has a blue and yellow wire. Fit that on the first stator, ensuring that the blue wires of both lighting coils are on the left or right, not next to each other.
6 Ground the yellow wires coming from these coils.
7 Connect the two blue wires at the connecting block.
8 You will now have 3 wires coming from the stator: black = earth, red = ignition and blue for the lighting, brake light and horn

The lighting coils with the thin windings and blue and yellow wires produce more than 25V. But they must be connected in parallel, NOT in series. Now all you need is a voltage regulator with 3 connections, and you have 12V AC.

Please note that your wiring must be modified after the 12V conversion.

Thanks Rowdy, I even had that saved but forgot about it. I put in a request to Greasy to see if he has another points stator to add to my junk pile he's making for me.