Modern Vespa

You might find this interesting.

http://www.vespa-klub.dk/Rally_CDI.HTM

Thanks! There are also reproduction Femsa boxes that look pretty similar.

It's good to know I can replace it. The original ones are so rare.

I feel your pain. As you have said it either works or it doesn't.

As others have said having a known working Cdi that you can test on the system so you can rule that out. Either get a repro Cdi or Jerry up a Ducati setup. Pickup would be next to swap out then the ignition coil on stator.

I guess I could just rebuild it all.

Mauro Pascoli, amazingly, has all the parts for the Femsa. But they only sell the parts, not the stator complete.

I hope one of my boxes works. I just like the original look. The repro ones are so *not* original.

I had Scooterwest, a really great shop, rebuild the stator. They test all the components and replace the wires.

But it could be that I broke a wire pulling it through, or one of the components is bad.

Before you start spending money, let's try some troubleshooting. This setup did run before you started your restoration, correct?

One thing I haven't seen is a mention of the kill switch. Can you remove the kill wire at the junction box and test for spark? What about switching back to a cap and not the brass yoke?

If you have to spend money, buy a multimeter. With Vespas it's only a matter of time before you'll need one to check voltage or continuity. Stop guessing and start checking!

If you can wait a little longer, I fly home Wednesday and can you get you resistance values off a good Femsa stator.

I do too. Actually the worst is when it sometimes works and gets you far enough from home and then stops working. Intermittent functioning is the calling card of the electrical gremlin.

You will get it. If I can, you can.

Btw, don't pull your stripes off. That's when the universe will smite you for being a perfectionist. There is a certain point where fixing one detail too many makes it all go to shit. Your bike is gorgeous. Trust me.

Thanks! I can wait!

I'll order a multimeter, and get back to it next weekend. That should be able to probably diagnose it down to one or two wires. Or definitely the CDI if those are fine.

I disconnected the kill switch. It's one purple wire that goes to the key switch. And also discovered that the Sipea NOS switch I bought is wired wrong. Turning the ignition on connects the circuit to the ground, which will kill the engine, right?

I think I can combine the new one with the old. Just keep the key part.

But disconnecting the wire should also work.

That ignition did get a spark when I bought the bike, but it never ran. There was rust in the tank, and a mouse chewed through the lead wire. but it kicked over and got a spark. Once. In 2016. The last time it ran looked like 1985.

I will keep the stripes! They are so close! And I bet the silver ones aren't exactly original. They're a $20 repro thing I found at Beed Speed. They could be the same exact ones but say silver.

It's good to know that all the parts are available, if I need them.

Correct. Purple wire from the key switch. When in doubt, take a picture with your cell phone of what you got and disconnect everything! That eliminates the harness from the equation (sometimes even repro harnesses are wrong).

Youre also correct that the switch completing the ignition ground when ON is a bad thing. When you kill the motor, youre grounding out the ignition. When the key turns on, that breaks the ground, and the system can work as designed. Why your switch completes the circuit when on, i can only assume thats for lighting? Made on a Friday by a left handed sweat shop worker? Once you get your multimeter you can test the switch poles and see if theres a way to make that work.

It's too bad. I found an NOS switch that is almost identical, but I guess the rally one has two terminals, one goes off, the other on.

I think I can take apart the old switch and use the key and barrel from the new one.

The old one is very weathered, but I bet I can salvage from the two.

I'll do this first, and then can put the tank in.

Thanks for the pics. It's all making sense now. That old key switch should work. The US market 74 Rally switches had 2 poles for ignition and 2 poles for lights off the battery. Thats why when you turn the key your ignition grounded. They were on the terminals for the battery. Swap them and try again, or wait for your multimeter and figure out which terminals make contact when the key is turned off.

I'll try it with the multimeter.

On the new switch, the two larger poles I have connected to the battery, and the three others to the ignition.

It's from an early Fiat 500 that must have a separate starter button, bc there's no starter position.

This is kind of cool.

I took apart the ignition switch, and it's so simple.

I can just swap out the key, and clean it up, and use the original one.

I love how simple these bikes are.

Out of the 5x 74 Rallys i've owned, I never saw Vespa or Fiat written on any of the keys. I'd have to dig in my box of spares and see if any of the spare switches have any distinguishing markings.

Five 74 Rallys!!

Curious. What colors were they?

My flywheel bolts had Fiat stamped in them. I guess they all used the same vendors.

Yea im guessing all the same vendors- CEV, Femsa, Ducati, Fiat?

2 were repainted, 2 OG white, 1 OG Maroon.

Here's the marking on my key

I love the leather key pouch.

The logo is from the switch company. Sipea.

I rebuilt my old switch. It's a little less tight and and new feeling than the NOS one, but it works.

One terminal turns on, the other off. The Fiat switch has two terminals come on, but it had the tumbler and ring.

I checked the tank, and the taps don't leak! So I can put that in.

Ok simplest of multimeter instruction here-

For the switch, turn the knob to the speaker icon. When the circuit is completed (probes touching), it will chirp. When broken, nothing. Touch two bottom contacts on the switch and then turn the key. If it chimes, that's the circuit you don't want. You want the one that chimes while the key is off, and then silent when key on. That's where you'll hook up your ground and ignition wire to. Since there's multiple contacts, you may have to try various combos to get what you need.

You see V with a solid line over it. That's DC voltage measuring. V with the wavy is AC. Once it's running you can measure AC voltage at each stage or see what size voltage regulator you'll need.

The omega symbol is resistance with various limits. 200 and under, 2k, 20k etc. If you measure 205 on the 200 setting, it's gonna give you a 1 or something wild. Turn the switch to 2k and measure 205 and it'll read something more appropriate.

The chirp works!

Ok! I can get it all back together, hook up the tank and wiring again, and all that's left is the CDI wires, and checking all the wires.

I might need a new CDI. I notice all the Italian restorations have them. Maybe bc it's better to get one now, then hope the Femsa still works when it's 80 years old. They also have a separate coil, and Scooterwest recommended upgrading that.

Sounds like your close. Fingers crossed.

Of all the steps to getting an engine running, electrical always seems to give me the most grief. Wonky ignition pickup on my Stella caused me no end of frustration. With my bus engine rebuilds, some nagging electrical gremlin would always slow me down. We're all cheering for you.

the forever project.

Lube the hose and try to feed it down through the grommet vs pulling the carb.

Cut a notch the width of the clip through the middle of the fuel tap arm and pinch down the end if you want the lever deeper.
I have a pic if you want.

Thanks! Those are both good ideas!

The original one has a slot and pinch. Not sure about this one.

I guess I need to pull out the tank anyway to get the fuel line.

The shape of the new fuel lever is a bit different, too. I think.

The slot might be hard to do without destroying it.

the paper one is, I think, correct for the GS/SS/Rally tank. the cork and rubber are too thick.

If I remember correctly, my SIP fast flow fuel tap was way too long, but it was drilled in 2 places for the pin. I cut it down to the same size as the old lever and the pin lined up. I would imagine they are manufactured for fitting on a number of models.

if you have the old lever, reuse it. it still ends up being a little bit long but at least the shape is better.

I clamped an angle grinder with a cutoff disc to a table at 90 degrees and fed it by hand. Pinched to friction hold tight. Went well.

With the original slot style you can pull/install the lever before/after pulling the tank. With the 1st generation autolube tank it's close to impossible to deal with otherwise.

Thanks!

I think I might try to salvage the lever from my other Rally (if I have it). That one is missing lots of parts, so will have to be more of a restoration from Pascoli parts.

I got super OCD with this one.

Sorry for the delay, wife's birthday was yesterday using the multimeter on only the ignition wires @ the 2k resistance setting-

R-B .680
R-G .450
R-black .169

B-G .830
B- black .700

G-black .328

Switching to the 200k setting I get 6.8 between the two pickup magnets. No continuity between the magnets and ground.

omg. thank you!

I will check these over the weekend. Maybe even get it running!

ok.

I tested the wires from my stator, at the junction box on the stator itself to the connectors.

They're all fine.

So I think that rules out everything but:
- Bad Femsa coil
- Bad coil on the stator
- A short on the stator
- Maybe I put the stator on wrong.

Would it make a difference if it the coil is rotated?

Seems like it would still spark, just at the wrong time.

That's correct. The stator *should* only fit properly one way. Unless the rally is a freak design (which I doubt), the top left mounting slot is a different radius so only that slot matches the screw there.

Stator orientation is good.

The tanks are always a bitch to install. I connect the fuel line to the carb last so that I can pull/push the fuel hose so the tank fits in easily.

Rally's did not have the under seat helmet hooks. Just the one above the key switch.

The tanks are always hard for me…especially the sight glass. The tank seems to get stuck on wiring in spite of trying to secure it out of the way. I use a little dish soap on it.

It must be the coil.

Femsatronic nightmare.

I tried all the wires on the multimeter. the power wires (the junction box) generate current. Or something measurable. Touching the multimeter to the two yellow wires. And yellow and white.

I think those all come from the same coils.

The grounds work. All the wires work from their ends on the stator to the the other side connectors.

The ignition ones to the Femsa generate no measurable anything. I tried between two, and between each and a ground. Nothing.

Very frustrating.

Re-checked the pickup gap.

You can buy the stator coils, and the pickup, but not a complete stator.

The upgrade replacements for these are 12 volt and have different wires, different flywheel, etc.

I am at such a loss.

I tried my third Femsa coil. It seems unimaginable that one of the three I have doesn't work. I tested one, and it did work, but years ago.

Seems like I might need to go through the stator, and check all the wires. Maybe there's a ground in the wrong place from the rebuild.

What resistance values did you get measuring the same combination of wires I did?

I tried all the settings, and looks like 0 on all of them.

There are two places to plug in. I used the 10 amp one. I'll try the other.

Been binge-watching Whiteone Racing (recovering from surgery ) and thought of your project. Looks like you're past this level of things..
Maybe provide some more clues?

Thanks!

I will watch!

I found a new stator. It's vintage, but looks perfect. I am hoping it works!