Modern Vespa

my plan is to test my CDI on another scoot at my mechanic. if the test scoot starts I am gonna chuck the LML stator and will order the already modified SIP stator for the femsa to 12v upgrade

I have a 20-20 carb on my rally 180. the stock carb on my rally 200 is a 24-24. Will the 20-20 carb work on the rally 200?

yeah, least that way you can fully rule the carb out if the same happens

same carb just larger air intake diameter, be a nice performance up grade should you wish to keep it there too

Spark/gas problems on a Rally 200? I had similar problems, please review this old thread.

Mine turned out to be the coil was intermittant, typical for these I understand. If you have the CEAB type you can replace JUST the coil if it's bad.

upside down

If yours is like this try another coil, just bypass the original to test.



I removed the old one, bit of welding & the new one fits in there fine.


Here's a dandy way to test(thanks for the vid, Vad), even works on the road. Keep the gaps a little tite to be sure & leave your cowl at home.

So how do you do that exactly? I don't have sound here at work... the motor's running, right?

Hey G... it's easy, and yeah the motor is running.. just leave one plug in the cylinder, take another plug and connect it to the wire... wrap some wire around the ends of both plugs and hold the loose plug close to the mounted plug and kick it.. you can see the spark and it'll start and you can watch the spark jump from the bottom end of the loose plug to the top of the mounted plug... turn off the lights and Party!

Ginch,

I was very frustrated with my randomly dying motor and after I couldn't find one of those neon spark indicators I thought I had, I came with this.

If you can see a spark at your 'external' plug, then you know you at least have Hi Voltage on your 'internal' spark plug. This doesn't guarantee you are getting spark in there(bad plug installed), but if you DON'T see external spark, you know there's nothing at the internal one either.



You'll KNOW if your coil/CDI is working & that made all the difference when I was stumped with intermittent ignition problems.

Nice thing is it's so small, it's now in my toolbox on my spare plug. That's right, I got BALING WIRE in my kit. Zip ties & duct tape as well.

James John

That's the shit... I want one!

Hey V oodoo

I actually read your thread before and I used your dual plug method to test my spark (Excellent idea, well done ) On my Rally engine the spark is barely noticeable when I kick the engine over, engine doesn't start. To make sure I am not using a bad external plug I hooked the same set up to my sprint and got a nice big fat blue spark.

I am assuming the weak spark is causing me all my problems on my Rally engine.

During my restoration I converted to 12V replacing the Femsa to Ducati CDI. The Ducati CDI is therefor brand new and I would be surprised if it was faulty. I am trying to find someone in my area running a 12V electronic ignition that I can plug my CDI into. Easier said than done though, vintage Vespa's are scarce here.

I want to eliminate whether I have a faulty stator.

The wiring diagram I am using is attached.

I am going to try to turn the engine over with a drill attached to the fly wheel using the flywheel puller tool.

Have I got the following right?

To measure the pick up signal I measure resistance across red and green and see if I see a change in reading when I turn the flywheel.?

To test the ignition coil I measure voltage across white and green?

Jinfu JUST posted this & I like some of the drawings. GREAT site!
http://modvespa.com/vespa-wiring-diagrams/

He's got this & another PDF for a '77 Rally and lots more

Some are almost art like this GS160 / SS180 example

Do you have hayband as well? Cool trick Voodoo, that is really going to save some frustration... I'll pass it on to five of my friends and good fortune will be mine.

Electricity + Vespa = headache.
I'm not sure but I found this some time ago, hope it's useful for you. Then there is this, specifically about a Stella/Belladonna (LML) stator, but may get you into the ballpark, though not neccesarily the good seats! -

Thanks Ginch, this is awesome, will do the checks tomorrow

Thanks again Ginch for your reply, the info you posted is invaluable and I will definitely be referring to this again in future if I suspect electrical problems. The resistance I read across the ignition coil winding was around 100ohms. I chucked the LML piece of junk stator plate and ordered a new 'pre-modified' stator plate from SIP. Once it arrived I installed and hooked up a 'V oodoo External Spark Plug', kicked the bike over and instantly saw a bright blue spark dancing around the external plug. All problems solved.

....And the prize goes to Cncjerry for predicting this problem right up front in the first few replies to my post

MAN THAT FREAKING FAULTY IGNITION COIL MESSED ME AROUND FOR DAYS

I'm glad it helped you too!