Modern Vespa

I'm going to come back to that first cowl later on but for now I'm working on the second cowl... but found a new problem.

The cowl has a LOT of little pinhole dents that almost look like the paint has been bubbling from below. In sanding them down, I've found a layer of primer and then a lot of what looks like rust. It is rough enough to catch a fingernail.
I'm wondering if the PO just shot primer over rust deposits and did a down-and-dirty paint job.

I'm going to spray a little Ospro on the bad areas to see what happens overnight but I'm concerned that the rust pits won't go away.

Any thoughts?

Unfortunately if you shoot any primer besides wash primer or epoxy primer, it'll bubble as it's porous. It dries like Swiss cheese.

So air comes into contact with the metal through the holes, which will always have water content, it will rust then delaminate the paint on top.

I always use epoxy primer now, done properly, it'll seal the metal up.

Granted epoxy can crack, it's important to use seam sealer in the right places. Also to mix it up at the right ratios.

Gotcha Ya Bastard!

Well, I didn't but my mechanic/friend Al got it for me. Back in March I gave up on trying to solve my electrical problem. I worked on it for more than a week and couldn't find the short but Al did it in less than an hour.

When I bought Red Rover, it had been partly disassembled, including most of the wiring harness. As part of the process, the PO had removed the rear brake switch so I checked the wires, installed a new brake cable and reinstalled the pedal on the floorboard... without a rubber gasket. There was no gasket among the box of miscellaneous parts that came with the scooter and I didn't know then that one was required so I installed it with direct metal-to-metal contact causing the short that was the source of all my problems... at least the electrical ones.

Al, found the problem, reinstalled the pedal with a rubber gasket and now all is good. Now I can get back to my painting project.

Right on!

Always nice to find a smoking gun. Especially when it's the source of a lot of problems. Especially when it's such a cheap fix.

It's time to play with the carburetor. Red Rover came to me with a 116 main jet with a BE4 mixer and a transition jet (is that the right term) that is marked "50". The scooter came from Colorado and is now in Fresno so I'm wondering if I need to change the jets for Fresno's low-altitude and hot climate. I put in a 114 main jet and Red Rover is zipping around the neighborhood but I worry that a 114 might be a bit lean. It's a 24/24 Delloto carb.

Any thoughts?

either the carb is a 20.20 or a 24.24 but there is no 20.24

coming from colorado to fresno, you will need more fuel = bigger number jets than the ones in the bike when you got it, assuming they were correct for that altitude.

the bike is stock - cylinder and exhaust? the main jet will depend on which flavor carb you have. the 20.20 will take a bit smaller than the 24.24

Oops... 24/24. I'll correct my original post.

Yes, it is a stock exhaust for now and the stock cylinder. I'll go with a larger jet instead of a smaller one... say 118... and see what happens.

Thanks for catching my typo

118 or 120 is probably ok with stock exhaust

I'm going to try a run around the neighborhood tomorrow with a 118 and see what happens. In the meantime I painted the gear numbers. I use a Whiteout pen which makes it really easy and it lasts about 2 years.

Very nice!

It's damned difficult to shift into 4th gear so, hoping that it's not a transmission problem, I'm going to replace the shifter inners and outers. I've done it before but it was a while ago so I'm looking for a refresher video. Can anyone give me a link to an appropriate video... maybe something by Robot?

Also, some time ago I read a Forum post that involved adjusting the cables using vice grips attached to the cables and to a stationery object, like a workbench. I've been looking but haven't been able to find that post. Does anyone have a link?

Have you troubleshooter why it's difficult to shift to 4th? Something jamming it in the headset? Pinch bolt at the selector box different than the other? If none of those, go for it and replace the cables. Could be old and frayed.

The vice grips/cable was from Voodoo. He had two vice grips connected with a bungee cord. That way he could put equal tension on the cables and be hands free! If you can sucker a neigbor to come over and do the same thing, you'll get the same result.

Had this happen twice, though for me it was first gear. Both times it was a shifter cable getting snarled up in the headset. It was really obvious when I looked.

https://www.youtube.com/shorts/4SWs06k0pFI

First easy thing to try is remove the shifter box cover and see if that makes any difference. It's "possible" a too-big pinch bolt was installed in its long history, hitting the cover (more shifting to 1st).

Next would be to pull the shifter box, if possible with the cables connected.

And don't be afraid to change the cable outers!
Front brake, clutch and shifter cable replacement to modern/performance cables & outers. Makes a big difference in riding enjoyment.
If you have a week or two I can post a video.

I'm going to start with the cables since I was going to replace them anyway as part of the rebuild. If that doesn't solve the problem then I'll look into the gears although they felt fine when I had the engine apart.

[quote="Ray8"]
https://www.youtube.com/shorts/4SWs06k0pFI

Thanks Ray8… that works.

Nice work on the shift numbers. Wondering if you ever got the air leak sorted out. Not to nag, but a good thing to revisit before you get too deep into jetting. Makes sense to sort out other things instead of staying stuck. Good to see your project moving along.

Oddly enough, the air leak just disappeared. I never could find it and neither could my friend Al who knows Vespas inside and out. I replaced all the seals and crossed my fingers and so far so good. As my friend SJanuary says, "Don't worry about finding the air leak… it will find you."

Glad you got it sorted out.

I just installed new front and rear brake shoes and yesterday I found that the front brake is shuttering when I apply pressure. I'm wondering if that is just new brake shoes breaking in or if I did something wrong when I installed the new shoes. Any thoughts?

I'm looking for advice on replacing the shifter cables. I've done it before but as I recall, it was a real pain in the ass. I was looking for a how-to video but couldn't find one

I remember that there is a copper clamp near the bottom so I'll have to pull the Outers out from below (right?) and since they are clamped will I have to pull both of them together?

I've replaced numerous brake and clutch cables s I know about using a LONG cable to pull the new Outer in while pulling out the old Outlet but I would welcome any suggestions for replacing the double shifter cables

I'm also going to check out the shifter box to make sure I don't have a problem there

I was going to do a video but I thought you'd already started
Replaced everything on my smallie yesterday. All I have to say after that experience is thank god for that split headset.

All you need in this post, but tying off both ends (in pic) keeps the new and old outers butted. Pull both down together.

https://modernvespa.com/forum/post1548841#1548841

I use for this a cable a little longer than the old and new sleeves together. With cable nipple on one side and holding and pushing/screwing with hand on the other.

Better with a solid 20 ga wire. A twisted cable will fray when driven through caked grease and damaged outers.

My new Inner/Outer shifter cables came with metal top hats but Red Rover doesn't use them (and neither have any of my other P200s) I'm guessing that they are to save wear and tear on the nylon top hats. Should I add the new top hats or just stick with the original nylon pieces? Or does it matter?

I finally got the old shifter cable Outers out and pulled in the new outers but I'm not sure about what I should do about the copper clip that holds them together. I'm thinking that I can open it up enough to slide over the ferrules, slide it down to the proper position and then crimp it in place but I don't know exactly how far down the cables I should slide it. I THINK it was about 20 inches down from the top end of the cables but I may have moved it while I was pulling it out. Can someone tell me where it should go?

My next concern is about sliding the cables into position with the clip installed. I had a hell of a time getting the cables out because the clip was getting hung up on something. Am I going to have that same problem reinstalling them? Can I move the clip higher on the cables so they don't get snagged on anything? Does anyone have any tips for the re installation with the clip installed.

I've heard of some guys replacing the clip with a zip tie. Any thoughts on that?

I don't have the clips at all and both bikes shift fine without them.
YRMV though.

I put some heat shrink around them.

It's not really needed, but it does help to keep the two cables from winding around each other as you fish them into place, and it helps to keep one from sliding down when a cable snaps.

I like the heat shrink suggestion and I'm going to go with that.

I spoke with Hot Rod Al yesterday and he too said that they are not really needed since the cables are secured at both ends.

There is three options:
1. With cap you showed
2. With big cap pressed on to cable
3. Without any cap, just metal cable end cap

It depends from mounting place in the gear knob.
My 1981 P originally have 1st type.
When I changed knob to non-indicator switch type I need to use cable without any cap.
And cables with big pressed cap is used in EFL and later models(IMHO) and PK.

Thanks Roland. I think I'm just going to go with the setup I found when I pulled the cables, that is with the regular ferrule tucked into the nylon top hat. It should work.

I really didn't need to replace the shift cables but since I'm rebuilding Red Rover, I figured "Why not do it… after all, how tough could it be?" (How many times have I gotten myself in trouble with that question?) Well, between losing the nylon top hat (Why do they always roll under the center of a parked car?), struggling with the copper clamp, and having the cables getting hung up on "something" in the tunnel, it's turned out to be damned tough!

Now, that I finally have the inners and outers pulled into place, it seems that the outers are too long. I suppose I could push them back into the body but I think I should probably cut them to the proper length. I've never cut a cable but I've seen videos on how to do it so I'll give it a try. After all, how tough could it be?

don't use side cutters. get a proper cable cutting tool for bicycle cables if you can.

It is easy as for me. Even with my old blunt side cutters. But if you have not practice, then it can be a little problem. Just try to cut few times on old outers maybe. Just don't push slowly, push it quick and sharp. Don't forget that outers must have right length. And better bit longer than shorter. When suspension works there must be margin of outers length. Also too short outers will be touch exhaust header.
Make sure that both outers is in its places in handlebar. Then push outers a bit inside the frame from engine side. Then mark where outers meets adjusters and add 5-7 cm and cut.

Here you can see how cables is routed.


I use SIP cables and never need to cut outers.

They shouldn't be so long. Have you routed them correctly behind the exhaust and installed a protecting sheath??

omg I always think that cables must be in front of exhaust...

125/150 in front, 200 behind…

I've got a good cutter, it's skill that I lack. I'll practice on an old outer.

Cut at Adjusters plus 5-7 cm... that makes sense.