Modern Vespa

Luck smiled on you! While it's not the worst job in the world, replacing a broken hub stud can be a bit of a kick in the nut.

I order nuts and washers in bulk so I'll never hesitate to throw one out if I don't think it's up to the job. Also, you'll find that quality parts in bulk are significantly cheaper than the hardware store, too.

Yea, good call. On my 2nd order I went the bulk route so I'd have plenty for the future.

Finally got around to doing some scooter stuff. We have competing cases of Covid and the flu in my household at the moment so the garage is probably the safest place for me…

I got my CA plate and reg finally so I was able to take it for a longer ride. It's fun how much time is spent at WOT on a scooter! It pulls pretty good and the speedo just touched 50 in top gear, and that was on a slight incline. Pretty good! My big question is how should I be riding it on long downhills? I was just pulling the clutch in and coasting, using the rear brake to keep my speed in check. Is this the right way? Or should I try and keep it in gear with a little bit of throttle?

I changed the gear oil today and it was a bit…greenish. Who knows when the last time this was done but I'm assuming the green tinge is from 2-stroke oil mixing in with the gear oil via a failing seal somewhere? Would love input on what you guys and gals think from the pics.


Quite a few spiky bits on the drain plug

This little magnet was on the end of the plug. I assumed that was by design to attract the shavings so I put it back that way.

Slight green-ish tinge to the drained oil

Another look. Cabernet Motulblanc, Pacific Northwest Vintage, 2000?

are you running auto lube or no? I like to pull the clutch in and give a few blips of the throttle as I coast, brakes are cheap and easy to replace.

anyway, how much gear oil came out? it doesn't look that bad TBH. how's it smell? however, that looks like an excessive amount. the fuzz on the magnet is pretty standard. somebody put the magnet there, but no harm in that.

Yeah, auto lube. Cool, I'll continue with the coasting and the blipping then!

About 350ml came out. I forget when it took the photo, but I also squirted some extra new oil through there and let it drain to kinda "wash things out" so there might be a little extra. I did undo the fill bolt first so it would drain smoother and oil started draining from the fill hole before I got the drain plug off. Maybe PO overfilled it a bit. I just filled it up until it started coming out the fill hole and called it a day. Smelled like…old oil I guess? Not too dissimilar from when I'd do other bikes in the past.

if a significant amount came out of the fill and overall the consistency felt thin and smelled gassy I'd be concerned.

otherwise, don't pet the sweaty stuff and carry on.

Yeah I figure since everything before me is unknown, I'll ride it for a couple months then change the oil again and see what we get. I can imagine seals will need to happen soon-ish (even if PO did them when he first acquired the bike, which is a big *if*, that would mean they're over 10 years old) and I'm just preparing myself for when things start to fail!

solid plan. things *will* fail. repair as necessary and upgrade where and when prudent.

ride it, get to know it, wrench a little and then figure out where you want to be with it. might turn out that you're totally fine with what it is and keep it that way while picking up another bike to tune and futz around with or restore. ya never know!

^^^ THIS

Get to know your ride for a while. I'd change the oil after a tank of gas or two. Since leaking seals is an unknown. An oil change is quick and cheap, and can give you insight to how the seals are doing.

Now that you've changed it, you know the fill point, etc. If it comes pouring out the fill hole, you know something is up....

Let my Vespa Jedi training begin…as soon as I can locate a PAL DVD player…

There are some good YT videos, too.

Here's a series from SIP.

This one is excellent. Scooterwest goes through the whole engine on this bike in a few videos.

Thanks, hjo! I've watched the scooter west series, it's great. I'll check out the SIP one as well.

That's what laptops are for. Or computers. I use a USB drive to play them on my Mac.

So the past couple times I've been riding since I changed the gear oil the clutch has been very grabby getting out of 1st gear. It was fine before the oil change, but maybe swapping out the decade old oil upset the fossils that are my clutch plates.

Figured this should be sorted sooner rather than later so I ordered a full clutch rebuild kit and all new cables. I think it comes with everything I need including new push pin, o-rings for the cover and arm and woodruff key. Figured I'd just rebuild the stock one for now and do something fancy/better in the future when I do a full tear down. My daughter and I are going to try to ride in the Hollywood Christmas parade at the end of the month (aka - lots of slow speed clutching) so I'm hoping I can get this sorted by then.

I think with books + YouTube I should be ok but any gotchas or advice would be welcome!

Sounds like you're on the right track. This is a good picture tutorial.

https://www.scootermercato.com/Garage/Tech-Tips/Large-Frame-Clutch-Rebuild

Also, replace the nut with one of these...
https://www.scootermercato.com/Scooter-Parts/Clutch-Misc-Parts/MODERNCLUTCHNUT

You'll need a couple specialized tools:
https://www.scootermercato.com/Scooter-Parts/Factory-Tools/T-30627
https://www.scootermercato.com/Scooter-Parts/Factory-Tools/T-31729

And one more: https://www.scootermercato.com/Scooter-Parts/Factory-Tools/T-20322

A really important thing is to not just pull the clutch out once the nut is removed. There is always a chance that the woodruff key could fall into the engine, and that sucks. Big time. Yes, I've done it, and friends have done it...

To avoid this, get the nut basket out first so you can look in there and see where the woodruff key is. Gently turn the engine so the key is up so when you do wiggle the clutch out the chances of the woodruff key falling into the abyss are lessoned, but not eliminated.

Hope this helps!

Often the clutch grabbing is wear on this part
https://www.scootermercato.com/Scooter-Parts/Hardware/113519
Add this to the basket.

Thanks for the info, qa. The rebuild kit actually came with all those special tools so I'll have them! I didn't know about the updated nut though so I'll pick that up. And great info for the woodruff key. Losing it in the motor seems like just my style so I'll try and avoid that. Thanks, Jack. Noticed the description of this part says for "non-injected bike with a P-series crank". Does that mean fuel injection or oil injection (auto-lube)? Also, is the crank on the VLB1M motor a P-series? I trust your suggestion I'm just trying to learn details like this. Thanks!

The description says suitable for VLB. The UK ones of that era were not oil injection but who knows with the US ones.
Depending on the individual tolerances even slight wear on this part could cause clutch grab. Change it even if it looks ok.

Can you elaborate more on this grabby?

At what point in the lever pull are you feeling the push pin (hard vs soft pull)?

While it's always been a bit of a stiff pull, it used to engage normally, in a fairly linear fashion once you hit the friction zone. Now, it engages all at once in the last 20% of lever travel and is unpredictable as to when it's going to engage. You can feather it and get going but it's not nearly as smooth as it should be.

cable stretching / failing?

Have you tried adjusting the cable?

When you pull the clutch there are two resistance factors. There's a light pull, which is the clutch lever spring. Next is a hard pull, once you hit the pin in the clutch.

You should feel the hard pull somewhere around 4mm at lever to headset. If you're much farther than that you may not be releasing the plates sufficiently.

"If I were you" I'd try adjusting the cable before diving into a clutch rebuild just yet.
After, with the ignition off and fuel drained from the carb (turn off the tap and run it till it dies), pull the clutch fully and kick it six or so times.

Thanks, Ray. I'll check this out the next time I get a chance. Would love for it to be a simple cable adjustment. What's the purpose of giving it the kicks with the clutch pulled after adjusting the cable?

to ensure that the cable isn't overly tight and causing the clutch to slip.

give a hairy eyeball to the inner and outer cable and make sure it's not about to leave the chat because when doing the clutch it'd be a great idea to go ahead and knock in a new cable if needed.

don't forget to soak your clutch plates!

Oh yeah. I ordered new inner and outers that I'll also replace if I end up going the rebuild route. Appreciate the help guys!

So I adjusted the cable using using the barrel adjuster to where the harder pull starts around 4mm out front where the lever meets the headset and took it for a ride. It started out smooth, jerked on me once, then continued to be smooth. I checked again after my 10 min ride and ended up tightening it a bit more. I'll ride again tomorrow and see how it does. I have two dumb questions:

Firstly, after adjusting the cable I did what Ray and Greasy said, run the carb dry, then kick the kick starter with the clutch pulled all the way in. When I was in neutral, it kicked through with no resistance. When I was in 1st gear the kick starter wanted to drive the bike forward. Does this mean that the clutch isn't full disengaging or is that normal?

Secondly, when I went to use the barrel adjuster, the lock nut was up against the adjuster part, not where it mounts in the engine case. This is incorrect, isn't it? When I was done I snugged it up like this. Is this correct? (Barrel adjusters are black magic to me, I can't wrap my head around how they physically work…)

Also, my headlight decided to peace out on me tonight so no more night rides for a while. Hope it's just the bulb. 🤷‍♂️

when you kick it over in neutral, don't touch the clutch lever. you want to see if it kicks through cleanly and smoothly, and turning over the engine-- ie. the cable isn't too tight and causing it to slip.

in 1st gear if you kick it over with the clutch engaged it may grab/slip a little bit on the first kick or two and try and move forward. that's fairly normal in that the plates don't immediately separate. as long as it doesn't drag when you're riding it then you should be fine. you are right, the lock nut should be right against the engine on adjuster threads.

how it works: the end of the inner cable is at a fixed point, the outer is in a stop (the barrel) as you adjust the barrel is creates or diminishes the amount of tension on the cable by moving the outer cable in or out. think of it like the draw string on a pair of sweats.

Backing the nut out a number of turns allow you adjust the threaded portion. Screwing the nut back toward the case puts tension on the threaded portion and prevents it from moving. It prevents it from going out of adjustment. Otherwise, engine vibrations might cause it to spin out of adjustment.

Is that a sealed-beam headlight?
Do any of the highbeam/lowbeam/taillights work?

(TL;DR - Clutch slightly better, headlight and horn no longer working, bike won't stay lit anymore)

Yeah, it seems like a sealed beam. I removed it from the headset and its all one unit with some kind of sealant around the inside edge with no easy way to remove the bulb. I was able to look in the front lens with a flashlight and it looks like the filament in the bulb is intact still so I think something else is going on. The horn also stopped working at the same time. High (or low?) beam has never worked since I got it but the tail light on/off and brake light and kill switch still work.

Seems like I'm waking up all the gremlins living in this scoot now because we have a new issue! The bike now won't stay running. It will start but only run for about 2-5 seconds before it dies. Here's a history of what happened today, with pictures:

Started her up this morning on 3 kicks, idled fine and had no issues. Rode down to the gas station to put some more gas in. Clutch was a little grabby (like it would wait to engage all at once toward the very end of lever travel) but not every time. Overall not too terrible and rideable. I put about .9 gallons in the tank and left about 2-3 inches of air in the top, trying not to overfill it. Kicked over at the gas station fine and I rode down to the post office, which was probably about a 20 minute ride, with no issues. Messed around in the post office for about 15-20 mins and when I came out, she didn't want to start. I (foolishly) had zero tools with me so I fiddled with the choke and finally it started up enough to where I could convince it to keep running by keeping the revs up with the throttle. I did open and close again the gas tank cap, thinking it was maybe something not venting properly (not even sure if this is a thing) so that may or may not have helped. It died on me two more times on the way home but I was able to limp it home using this method. Not ideal!

After I got home, here's a list of things I've tried (pics below):

1. Pulled the plug to inspect. Looks...ok? The insulator is slightly browner than in the photos but would love some opinions.

2. Checked the plug gap. It was about 0.28 inches so I closed it to the recommended 0.23 inches or 0.6mm.

3. Checked for spark by cranking over with the plug in the HT lead while held against the engine. Seems to be sparking fine.

4. Loosened slightly the cap on the float bowl (not sure what it's called but I circled it in my pic) to make sure fuel was getting to the carb and some fuel immediately came out so I tightened that back up.

5. While I was in there I took a look at the jetting. From what I've read on scooter help, it doesn't seem to be stock. But, scooter help also says the Veloce comes with a 20/17 carb, but mine is a 20/20. I've seen other resources say Veloce came with a 20/20 so I'm not sure if my carb is stock or someone added it afterwards.

6. Pulled the cover off of the handlebar switch to take the kill switch out of the equation. Thought maybe it was messed up and always making that connection to kill the bike. Didn't make a difference.

I'm wondering if the headlight and horn dying is related to this issue or not. Since I seem to have spark, maybe not? I dunno. I have NOT done something as simple as upping the idle, since all seemed to be working fine up until now, but maybe that's a simple solution? I just don't want to be band-aiding an actual issue.

Any and all thoughts are welcome and much appreciated!


***PM UPDATE*** - I got her running again! I blew out the vents in the gas cap with compressed air, I put in a new plug, and a slackened the clutch cable a bit (honestly I think that's what did it) but I got it to start and run again. I'm going to let it sit tonight and try and start it again tomorrow and we'll see how she behaves. It was a "Hey dummy, it was working fine, what's the ONE thing you did? Maybe undo that a little and see if that works..." lol. I'm sorry you all have to witness my slow learning. We'll solve the electrical and clutch grabbiness another day...


Plug pic 1

Plug pic 2

Is this too full for the tank?

Fuel came out of here when I loosened it so it's at least getting to the carb. Maybe not quick enough though...

When I put the air cleaner back on, it sits on top the jets a little and seems a little crooked but didn't seem to fit any other way. Is that right or am I missing something?

Current jets

Bonus pic of me making car drivers angry

Yep.

Pull the switch and have a look at the wire connections.
Do you have a multimeter? If not, you could just try fiddling with the wires with the engine running and see if you can get the headlight to work. Horn and headlight share the same power supply at the switch.

Did you pull the choke after 15-20 min?
Bunch of smoke after you finally got it to start?
Try this:
When parking, turn off the fuel and let it run for 30 or so seconds (or as soon as the revs start to rise) and kill it. As the fuel level in the bowl lowers the jetting will lean, and revs will increase until it dies. More gas in the tank is also more gravity pressure on the needle. If your needle is leaking even slightly with a full tank/full bowl it can flood.
It "should" start first kick no choke 20 min later.

Sorry adjusting the cable didn't help.
It can get tricky removing a clutch in-frame. I was hoping you could avoid that dive and ride it a bit more for now.

Really, no apologies necessary. I'm still getting familiar with this machine and I'm totally grateful for everyones info and suggestions. As you all know, it's hard when you have zero history of the bike, every problem could be 1/100 things. I'm having a good time learning as I go. I did try with and without the choke when I was trying to start it after the post office. I forget which position it was in when I was able to get it running. Thanks for this tip though, it made me realize I may have not turned off the fuel when I parked, and that could have contributed to the hard starting. I like your idea of running the carb almost dry when parking, I'll give that a go.

RE: headlight/horn; I do have a multimeter but I'm not exactly sure how to use it to test connections. I'll try fiddling at the switch and see if I get any results.

RE: grabby clutch; I was also reading the service station manual and it mentions a grabby clutch could also be the result of not enough oil in the bike. I noticed my bike leans slightly right when on the stand, so I leveled it, then topped off the oil. We'll see if that makes any difference. If not, then I'll dive into the clutch at some point. (You'll know when because I'll have a million more questions I'm sure, ha!). Much appreciated, thanks Ray!

Your carb is an old version of 20/20, makes sense, probably original. The filter is most likely for a newer model and doesn't quite fit. Work out what's touching and Dremel it.
The bigger issue. Your scooter didn't come with those jets. Keep the 50 pilot as it has remote air. The main stack parts you have are not meant to be together. What works best in a 20/20 is AC140/BE5. Keep with the 110 main jet but the final one will be smaller. Most likely 102.
With this jetting and the mixture screw adjustment, it's going to be 90% of the hot starting issue.

Thanks for the info, Jack. I will order some new jets and make the swap. Should I also check to make sure an aftermarket top end hasn't also been installed? I haven't taken the cowl off yet and I don't even know how I would tell if it's not original. Any pointers there?

Also can someone please identify the parts circled in my photo below? According to the parts manual for a Sprint, I assume #2 is the HT coil since it is connected to the spark plug, but it looks different than the pic in the parts book. I can't find #1 in the parts book at all. My bike is a '71 Sprint with a '75 Veloce motor. Is it just different for the Veloce or did someone change stuff?




Parts book pic

1 is a 6v regulator someone added in its history.
2 is a replacement/aftermarket 6v coil.
Can you pull the junction box cover and the headset switch and take a few pics?

An SIP Vape static 12vac ignition would be an excellent upgrade on that bike.
You'll need a few tools, 12v bulbs, and a simple 6v regulator if you want to keep the stock headlight for now*.
https://www.scootermercato.com/Scooter-Parts/Electronic-Ignition-Kits/510061RA_2

*Or this:
https://www.scootermercato.com/114435

if it's alum. it's aftermarket and it will be marked.

if it's iron, the barrel would probably be stamped on the base near the spigot. piaggio symbol or with a mfgr name. but some big bores didn't get stamped, so you should measure or see if the piston has #'s on it. more than likely it's just stock.

Thanks, Ray. Below are pics of the junction box and switch. I also took the cover off cylinder and took some pics. While doing that, I checked the points gap (it was off, so I adjusted that) and that exercise alone makes me want to upgrade to a VAPE system. Pics below of the cylinder. It has a Piaggio stamp and 150-GL stamped on the underside of the head, which makes me think its stock, but from a GL? The cylinder is kinda grey and shiny but I don't think it's aluminum. Which begs the question, why would someone muck with the jetting if they're not changing anything else? I guess maybe if they lived in high altitude...?










Self pulling flywheel with no circlip. Greeeeeat.

My guess is that they were trying to jet around an air leak, which is what I suspect you're now trying to do, as well. At this point, I think you really only have two options:
1) Pressure test it and determine if it's leaking
2) Do a soft parts rebuild (seals, buffers, o-rings) and then pressure test it

Until you know what you're working with, you're going to be chasing ghosts until it leaves you stranded and you're calling someone to come get you.

I 100% agree with Ray8 that the Vape would be a solid upgrade. I run the "sport" (variable timing) version on all my bikes, and it'll give you a little bit more power on the low end of the curve, but you have to be able to set timing on it, which some people seem to struggle with.

If it were me, I'd just replace the harness with a 12V and be done with it. Someone has been in working on that wiring in the past, so you're going to need to go through and validate every circuit to find what was done or replace the harness, which is probably less work with a more definitive payout. If you go that route, though, I'd suggest the BGM (scooter center) rather than SIP version, though mostly for the quality of the documentation.

The challenge with these bikes is that they're made of fifty or sixty year old parts that were never supposed to last more than about ten years.

I'm very much in agreement with you. The bottom line is I *know* (and knew when I bought it) that it needs a rebuild, it was just seeing how long we could put it off and maybe ride it a bit. But I think the right thing to do is tear it all down, and build it back so I know what I've got.

I know it's more than common for someone to get overzealous, buy an old scooter, tear it apart only to sell it for 1/4 what they paid 3 years later in boxes because they never got around to it but I don't think I'll fall into that trap. A big part of the reason I bought it was to learn to work on it and have something cool at the end of the day I can ride and be proud of for building myself. (I can always have a pro shop bail me out if I really get into a pickle).

I still have a ton to learn, but with YouTube, shop manuals and your all's willingness to continue to answer my noob questions, I think I can get there! Also, I like to go fast so…chandlerman I'll be looking to you for go-fast parts suggestions when the time comes!