Modern Vespa

Here is my other recently aquired project: 1981 Vespa 100 Sport.

I found this scooter listed for sale here in Sunny Socal. Not running missing parts, sitting on the hubs in the grass on the side of the house. They said it was a family members, and had been sitting in storage in Oakland area for about 10 years, before being recently brought down to SoCal...honestly not sure, as there is no plate or papers. But it isnt rotted out, and the motor still turns. I low balled em, they accepted. $150 changed hands, and they even loaded it for me! It definitely needs some TLC, and a few parts; of course some hard/impossible ones; but overall I'm happy. Especially for the price! I was not really looking for another project right now, but how could I not! I want to ride!

This is my first smallframe, and I've always loved the 100 Sport. Nice little quirky details, and my first scooter friend waaaay back in the day had a 100 Sport. We rode together many many miles, so they have always had a special place with me. Here is my new red and white Sporty

Here's the plan as its coming together.
I just got this a few days ago, so I'm sure this will evolve after some input from the SF experts

Engine turns free, has good compression as far as I can tell (will check with tester), plug is still a bit oily. Gonna peak inside cylinder with my Endoscope.
We'll atleast see if it'll spark up, then we can see if its road worthy.
Rebuild carb: its got some nice hard varnish inside
New battery, coil, spark wire & plug
Fresh gasoline and 2stroke oil
Cross the fingers and Start the engine!
I'm already planning it might need a tear down and rebuild after sitting so long, but lets see what we can do with it as is

New brakes F+R
New cables all around
New or rebuild shocks F+R
New seat cover or new mono seat (preferred!)
Sort out some type of signals, as originals are missing
Figure out something to replace the battery side door. Time to refresh my fabricating skills!

Oh and sort out the legshield dent(s) - see pics below...

I'm sure there's more. There always is. I have a plan - kinda

Gave the new Sporty a good wash

It just like when i have my smallie 2 year ago, with a fresh fuel i can make it alive but sadly when i go to first gear the bike jump due to 32 year drying clutch.. Have to change the clutch plate and it running till i have to change the bearing one year ago.. Making it run is easy, making it fast is hard if its for me

Good luck with the little 100 and cheer

Pull the tank. Inside tunnel is clean and rust free. Lets check the carb

Some concerning warped and dented areas on lower legshield center tunnel. The rest of legshield and tunnel looks ok, but not perfect. Not sure what is going on here. Maybe its been hit, but cant see evidence anywhere else... only these large dented portions. No bondo on front legshield or inside of tunnel/legshield fron what I can tell. Scraped away paint down to bare metal in a few spots all around here - no filler. One respray of red/white over the original factory beige. Gotta dig deeper and take some measurements....

Just a recap of the missing parts. Some I would like to aquire, others I can do without. Not going concours with this one. Right now I just want to fix to ride!

Front Vespa Badge
Rear 100 Sport badge (i know I know...)
Battery Door (i know I know...)
Engine Door
4 Turnsignals
headlight ring and glass
steering column lock
Coil/wire/cap
storage cubby underseat
floor runners

I like the colour

One of the coolest of the vintage speedos. Glows an eerie orange

If you find you need to change any of the cable outers you are going to have to remove the headset. If that is the case, strongly suggest you check and re grease the steering head bearings. Be sure to look carefully at the bottom races for ant pitting.
While it's apart pull the front suspension out of the fork and check for rust and dry bearings. Chances are good that the o ring seals have turned to dust and are gone.
Also check the fork for straightness.
You might feel like you are opening Pandora's box but in the long run you will be sure all is safe.

Thanks for the tips Exmayor! I do need to change the cable outers and inners, so thats good to know! I dont mind opening Pandoras box for safety peace of mind. Already planning to pull the headset/fork/front suspension, as I can feel some 'grittiness' when turning the fork and compressing the suspension. Will clean and replace all as needed to get it mechanically fresh and clean.

Btw, Lady in Red is a beaut!

Thanks
When you go to pull the front axle remember that the speedo pinion/nut combo is LEFT HAND thread. Learned the hard way!

Lefthand thread noted!! Thanks for saving me a hard earned lesson

A little progress today:

Checked the compression, 120 psi. Not too shabby!

Had a peak in the cylinder with my cheapy endoscope through the spark plug hole, just for fun. Some scoring, coked piston top as expected. I think pretty clean overall. Excuse the poor pics. It was hard getting a good photo in there with the angle of the plug hole.

Disassembled and cleaned the carb. Soaking the main body overnight to get any varnished gas out of passages.

Next up! It needs an HT coil & battery to hopefully turn over. Based on what I can tell, the only reason this motor isn't running is because the HT coil is missing... who know's why it was removed. I have an old prima one in my box of misc parts, but not sure if it is any good. We'll see! Will most likely go to CDi conversion but want to start it as is before modifying anything.

Here is a closeup shot of the 2-tone paint. Solid red and fine glitter white. Whomever did this paint back in the day did a good job. Its too bad it got knocked around so much, but I'm gonna bring this back as best I can. Retouching/repainting the solid red portions should be easy. I have some experience with auto paint. I'm not as sure in matching the white... Scrapes and scratches add character right

On cleaning the carb. If you know someone with an ultrasonic cleaner it's worth using. I ran mine thru for an hour using hot water and simple green. Thought it was clean after spraying carb cleaner thru it but there were still little bits of residue in the bottom of the tank.

Carb's clean and back together. Dried up gas wasn't too bad. Soaked overnight for peace of mind. Blew it all out with the compressor and should be good for now.

Today I worked on the electrical system and wiring. The factory harness is mostly unharmed, save for a few minor things like the turn signals being removed, missing brake light bulb, and missing HT Coil. I like to give any new project of mine a good once over to familiarize myself and make sure everything is in proper order. So with multimeter in hand, I got to work.

I dont have the proper battery yet, so for testing purposes I hooked the sproty to a car battery and got to testing. 12v power-check! 12v at the ignition switch-check! Slow burn of smoke from iginition switch-double check!! This is why we check Consult wiring diagram, reference very handy factory sticker inside headset; and realize that green wire should be on #8, not #6. After switching that, sorting and organizing the bundles in headset all is good! Checked various spots with multi meter to be sure power is going where it should when it should. Brake switches work, but rear switch is intermittent so will need replacing.

Turn signal leads get power properly from the switch, front and rear.

The leads for the front signals were cut off short in the headset, near the throttle tube on right side. Both the blue/right and brown/left leads for the front signals are inside the loom on the right side of headset, and cut short. To me this makes sense for the right side lead (blue), but for the left side(brown) it seems weird that the wire would go to the right side, then loop over to the left. Seems a waste of wiring?....

who knows proper routing for these? I have the wiring diagram, so not worried about the circuit. Just want to know how these wires were originally routed from factory.

Removed and replace the horn, which was not working. Closer inspection reveals why...

Good thing I have a spare in old box of misc parts. It pays to save (parts).

The old coil from my parts bin seems to be no good. So Next up I'm going to order a new HT coil, wire, plug, battery, and a few other misc bits

So you say you need a battery door. How good are you at metal fabrication or now someone that can.



https://www.scooter-center.com/en/7676197/side-panel-rear-lhs-oem-quality-vespa-v50-v90-since-1968-pv125-since-1968

RowdyC: Thanks for that link! I saw you offer this idea on another 100 Sport thread, but cant remember which one.... it was green

I can do the metal fab work, just need to dust off my skills as its been a little while; but I've fabed and welded my fair share of stuff on various projects. I even took a college course on metalwork and welding back in the day, just so I could do my own work properly. Time for a quick refresh

If I can't find an og door, which is likely; I'll be fabing one up from this frame half as you suggested. Good tip!!

What does a batt door go for?

When they show up, which is basically never; I've seen some go for multi-hundred's....I'd prefer to have an original door over fabbing one; but I'm not affraid of the work. My son and I are working on this Sporty together, so it would be a good opportunity to teach him some new skills. We found this scoot together for a summer project, and got a great deal; so we do have some room in the budget to splurge on a few things. I'd prefer to spend on going fast and stopping faster, instead of sheet metal...we are forming a plan as we move along. First priority is to see if it will run, then we can tear down/refurbish/rebuild as needed. Will keep all stock for now.

Next up is bolting on new coil/wire/plug, (thanks Scooterwest!) new battery, fresh fuel, and hopefully my son will get his first kickstart experience. Stay tuned

Time to ramp up the fiberglass R&D

I smell opportunity!

YES!! had given this a thought as well.... I really like learning new skills too

SoCal, is that fiber door yours?

For such a scruffy scooter, I gotta say that motor is amazingly clean. Much cleaner than any motor on any scooter I've gotten hold of I think.
That's gotta be a good sign.


Me, I am currently removing 1/4" of old oil & Italian dirt from a motor, much of it like low grade cement.

Voodoo:I agree! Cleaner than any other Vehicle of any kind that I've ever had. I hope it is a good sign.

Right now I just installed the new (aftermarket) coil, and getting no spark. Chasing gremlins....

Installed new aftermarket coil, but getting no spark. I do not know if the condensor and/or stator is working or not. This is all first try on this motor to see if I can get it to run, before cracking anything open or replacing anything.

Below is a picture of my engine/stator junction box:
Key ON, kill switch in RUN position
Wires from right to left
PURPLE: 0v
RED: 12v
BLACK: 0v
YELLOW: 12v
GREEN: 0v
** not shown is the jumper wire I added from the GREEN wire-to-Coil.
**** yes the stator wiring looks terrible and will be rewired before taking her out. Might have to just do it before she sparks, and possible upgrade to CDI at same time.

Are these voltage readings are correct? Should I have 12v from the green wire at all times when key is on, except for the moment the points open?

New aftermarket coil resistance reads 6ohms, between the 2 leads.
- I know its best to check spark with a known working coil, but I dont have any others that I know work.

I'm also checking to see spark with the heavy wire trick from Voodoo-thanks for sharing the good tip! Which seems to be better solution than the old "try to hold plug against engine case while also kicking and trying to see spark without getting shocked" method.

Coil was missing when I got this scoot, so maybe the PO was trying to chase down this same issue, which led to it sitting for over 10 years..... maybe bad condensor &/or ignition coil? these charging systems are not my area of expertise...

The green wire should be sending voltage to the coil when you kick the engine over. If it's not, it's grounding somewhere. Not surprising considering the state of those wires.

Check the green for continuity between the junction box and the key switch, and between the junction box and the kill switch

Try disconnecting the kill switch.

Does your wiring match this diagram?

yes, my wiring does match this diagram; which I downloaded from Scooterhelp. That is what I have been referencing as I check things out.

I checked voltage of green wire while kicking over, and show's nothing. So probably grounding out as you said SoCal. I'll check continuity as suggested.

Pulled the flywheel and stator. Definitely needs a rewire. Time to hone my soldering skills

Some believe the green insulation on 80s Vespas was made of recycled cheese or some kind of pasta.

Old moldy Penne seems about right

Ordered stator rewire kit, as I didn't have all the correct wires/terminals,etc for this small job. Cheaper that way right....but a few of the wires are too short. It was a P-series kit, which had the correct wire colors; but (unknowingly) not the right length. So now I'm waiting on some bulk wire, terminals, and a new crimper. Good excuse for a new tool and supplies.

I got a few other bits in the mail, so while I'm waiting I'll clean out the fuel tank and install the new tap. Inside is just a little dirty....

need to rinse it out and maybe do a rust treatment. The top of the tank looks much worse than the inside.

Phosphoric acid for the inside & outside?

BTW if you haven't found a source you like yet, these guys have great quality crimp connectors and tools:
http://vintageconnections.com/

It makes a huge difference to work with quality connectors, wiring is a snap these days since I found them.

I can't say if the quality is as good, but I got these and they work great!
https://www.amazon.com/gp/product/B07FCFH84Q/ref=ppx_yo_dt_b_asin_title_o08_s01?ie=UTF8&psc=1

so long as you've got a good crimper (and it looks like you do), then those should do nicely. a proper tool makes that job so much better.

Thanks guys! I ordered a crimper, connectors, and a selection of various colored wire from AMZ. Should arrive Sat. I did previously find the Vintageconnections site -thanks for that! Will go back to them in future, as they do have the correct size 9mm black pvc loom/sheathing used on the stator (which i cannot seem to find any where else...) and obviously all the other bits.

I'll reuse the pvc loom from incorrect rewire kit I ordered.