Modern Vespa

you may want to try shimming your box out a bit as a last ditch effort. you can put thin washers in between the box and the case and see if the selection is better (but you can't run the engine that way). you can test the selection by moving the batwing while rotating the wheel.

on my px I think i have 4 or 5 gaskets under the box to get better selection. they do make actual shims for the job though, if it works out.

Have you driven it and tried to shift? Or is this all on the lift by turning the back wheel?

Thanks sdjohn, I'll try that.

This is encouraging. With bungee in place tensioning both cables and pinch bolts loose, can you freely rotate your shifter full range from just before 1 to just past 4? If no, your problems are likely with the cables or up in the headset. If yes, it would seem the problem is at your shift box. With cables loose or removed and rear wheel off the ground so you can rotate it, can you manually shift the batwing thru all four gears, with detents matching up to being solidly in selected gear?

Yes, I ve been riding up and down my street trying to shift. It's a pain in the ass rolling the scooter on and off the lift and then jacking it up and down lifting the wheel off the lift surface but I figure that's the only way to test it.

Yes, the cables move fairly smoothly from 1 to 4 (but I'll double check that tomorrow). I can't move the batwing by hand… it's too stiff. Should I be able to? I use a screwdriver to move the batwing through the gears and moving it into 4th is tough even with a screwdriver. I've been assuming that that is normal… am I wrong?

Here is another idea - Spermy shifts good, correct?

Maybe you can try to shift Spermy with the back tire up and see how it feels. Try moving the batwing on Spermy, and use Spermy as your baseline to know how the shifter is supposed to work.

That way you'll answer a bunch of questions about the shifting box.

I know, I know, PITA, but you have a good example of a working machine to compare to....

Trying to help from afar ...

Thanks qascooter, lm planning to just that

Hmmmm,,, you are rotating rear wheel and rotating batwing for 4th is still a lot harder to get into than the other gears? Sorry but yeah you are wrong - it's not normal, that ain't right! Like qa says, compare batwing action w/ Spermy to verify.

If you find that's the difference next thing might be to pull the shift box and confirm the shift rod slides freely to all gears, it could be bent somehow. If it does slide properly, I'd be tempted to swap in Spermy's shift box and see what happens? I guess it's always shifted like this, problem isn't new? I'm beginning to think your shift box is pooched...

BTW, that setup is some lock jaw, bungee cord slinging goodness.

If Chris, the safety officer, sees that setup, first thing he'd say is "where's your safety glasses?"

Are you sure the replacement rod and washer are exactly the same total length?

That's something you should be able to check without splitting the cases. Compare the length of the exposed shift rods when both bikes are in the same gear. Also spin the rear wheel and move the shaft through all the gears. Compare feel for both bikes. Finally, swapping boxes.

Good luck.

Yeah, yeah, yeah. You're right of course but remember, I'm Old School. Just look at my avatar, taken when I was 16... "Helmets?... We don't need no stinking helmets!"

Thanks all. You've given me a lot of ideas to work with and I'm going to try them out as soon as the garage warms up a bit. Right now it's too damned cold for this Native Californian.

It snowed here for the first time already. Feels like February! Not cold enough to play hockey outside though sadly. This might be the year though.

The weather was tolerable here today so I installed Spermy's gear selector box in Red Rover and it shifter MUCH better. It wasn't perfect but it was definitely better which tells me that I need to replace Red Rover's old selector box... if I can find one. Scooter Mercato doesn't have a selector box with the screw-in neutral switch nor does Scooterwest Nor Scooter speed. Does anyone know of a supplier who might carry it?

I've found selector boxes with a built-in neutral switch but I don't know anything about them and would prefer to stick with the screw-in type. Does anyone have any comments about the newer version, Yea or Nay?

Says 9 in stock

https://www.scooterwest.com/selector-box-early-vnx-vsx-up-to-83-no-neutral-light-fits-earlier-series-p125x-p200e-1965857.html

Yes, I saw that but it is the one with the built-in neutral light switch instead of the screw-in one and I don't know anything about them. It uses only the brown wire so what happens to the black wire?

The black wire is a ground, so it can be ignored.

And it looks like the same box here https://www.scootermercato.com/Scooter-Parts/Selector-Box-Complete/87046_2

Yes, I saw that one at Scooter Mercado too and it is still the same issue with the neutral switch. I don't know if these newer built-in ones will work with my OLD model.

I don't read wiring diagrams well, so it looks like the black ground wire should go somewhere. Would I leave it just dangling at the switch? What about the connection at the bulb…. the brown wire to one terminal and the black wire to the other even though it's not connected to anything?

I hate electricity.

I haven't used one of those selector boxes, but I'd connect the brown wire and the selector box should be the ground, so the black can dangle or be cut back in the harness. Theoretically that is...

Does your new selector box have 2 electrical terminals or one? I'm not familiar with the newer style. I am assuming there's only one electrical terminal since you are wondering what to do with the ground wire.
If it only has one electrical terminal, then the selector box is providing the ground to the switch. If it has two, like your old switch, then you must connect both brown and black wires to the switch. The neutral light switch is switching the ground side of the circuit of the neutral light. So you must have both wires connected at the bulb no matter what. Your old switch got its ground from the black wire. Your new switch is getting its ground from the selector box itself. I would put a ring terminal on your black ground wire and ground it to the selector box mounting stud. If anything it will give your engine another good path to ground. Much like a ground strap.
I would also take the headset cover off of Spermy and compare the gear selector cable routing with Red. I discovered on my 1980 P125X that the previous owner had the shift cable ends inserted in the wrong holes at the shifter pulley. This caused some binding and very hard shifting! I can't believe it even shifted at all! Once I got that sorted it shifted like it should.

Good luck!

Hec

Do you need the neutral light to pass inspection? I thought I did, as well as a kill switch so I cobbled together a working kill switch. I'm the end, the inspector didn't look at either. I think either would work in terms of the electrical. You can also buy replacement switches. I don't remember which type is available.

Sounds like you are getting close and it's the box at fault.

I haven't bought a new selector box yet because I haven't been able to find the older version with the screw in neutral light. If I have to, I'll buy that newer one but I would rather not because I sometimes have compatibility issues with newer parts because Red Rover is so damned old... 1977. If I do go with the newer box, your explanation will be very helpful. Thank you for that.

I've compared the cable routing on Red Rover with Spermy and all is good in that department.

Fatear5

No, I just like the neutral light and I want to keep it.

FWIW, I took my crusty selector box and put it in my ultrasonic cleaner with Simple Green Purple(Aluminum Safe) degreaser in it. I had the water temp at 150F. I ran it through at least 3-4 30 min cycles. Each time it went through more and more of the dried up 43 year old grease got dissolved. Now it moves nice and smooth. I recommend that you try that along with two new shift cables and see if that works. If you don't have an ultrasonic just boil some water and add the degreaser to make some gear selector box soup! Just do it when the wifey is not home! I am using the SIP cables and they are silky smooth compared to the OEM ones. You can order just the shift cables from Scooter Mercato if you don't need the whole set. I would also replace the shift pulley at the handle bar. This in my opinion should do it! You shouldn't need a selector box unless its wore out and has too much play in it.


https://www.sip-scootershop.com/en/product/cable-kit-sip-performance_94180400

Hec

Unlikely that the selector body is junk. All the parts that wear can be replaced. Rebuild kits are available.
https://www.sip-scootershop.com/en/product/selector-arm-selector-box-inner_12135400?
https://www.sip-scootershop.com/en/product/selector-arm-selector-box-top_12135800?
Unscrewing the pivot is definitely the hardest step.

I don't really think that the selector on Red Rover is realliy bad... not too dirty, in fact my mechanic says that the selector is fine however the bottom line is that it doesn't shift well in Red Rover or in Spermy. I installed it in Spermy this afternoon just to see if the selector was the problem and apparently it is. Shifting is really stiff when I use that selector in either scooter. When I put Spermy's selector in Red Rover, Red Rover shifted much more easily so I'm going to replace the selector.

I've learned that the old shifter with the screw-in neutral light swith is no longer available so I'm going to go with the newer one with the built-in switch. I've been assured that it will work in Red Rover.

I couldn't find those SIP teflon cables so I ordered the regular inners and outers from Scooter Mercado and they seem fine... not "silky smooth" but not bad.

The pulley in the headset seems fine too so if a new selector smooths out the shifting, I'm going to leave it alone.

Thanks for all the suggestions... I appreciate the help.

Looking at your selector box closely points to a worn out roller. That roller looks like it has steps or grooves worn in it. This could be your problem as the grooves will not allow smooth operation of the batwing due to the smaller ID of the roller grooves. Like rolling over a pothole with 8" tires vs 10" tires!

Hec

If the roller has that much wear, I bet the pivot is worn about half way through its thickness.

Roller isn't critical, more important is the pivot. That's the only thing holding the position of the paw.

Gears will jump if there's too much play in the pivot.

I'm with you on just getting a new box. You can futz with the old one later when you have some time.

I also like to have all my idiot lights and speedo working too. It's kind of a pet peeve (among many). I have a warning light on my VW bus that I just HAD to fix. It tells you whether or not both brake light switches are working on the master cylinder. It only needs one. I fixed it because I could.

Glad it's only a box issue. Happy motoring.

Yes, that's the plan for now. I'm going to order a new selector from Scooter Mercado today along with the parts to rebuild the old one. Always nice to have a spare.

Gotcha ya bastard!

I bought a new selector box and installed it yesterday and it feels like shifting is substantially better. Of course, it's been too cold for me to do more than ride up and down the block so I don't know if the problem is solved but I'm encouraged. I still need to do some tweaking but I'll save that for a warmer day.

I haven't messed with the neutral light yet but you guys have given me some pretty good instructions so I'll see what happens next

The only hiccup that I had was installing the pinchbolts. The slot in the new box is a little too narrow and the pinch bolt doesn't seat all the way at the end of the slot. Normally I would just file the slot a little wider but I had already installed the box and I didn't feel like taking it off again so I filed down the pinch bolts instead. I'll correct the slot in the box the next time I have to remove it.

I bought new parts for the old selector box and will rebuild that a little later on.

Glad you're making progress.

Always modify the cheapest part. 🙂

Can't really tell from the photo (usually pokes out quite a bit…), but you have a new selector box gasket?

'

The new selector box has solved the shifting problem. It's still a little rough but I can now run through all 4 gears. I can tweak it later

Oddly enough I'm having a problem with the neutral light. I connected the brown wire to the new single-contact terminal and the neutral light is on, but it's on all the time… through all 4 gears.

What's more troubling is that the neutral light stays on through all 4 gears even when the brown wire is disconnected. Both the brown wire and the black wire are just dangling but light is still on and I don't know where the power is coming from. I'll try to find the problem but unless it's something obvious, I won't be able to identify it.

First place I will look will be at the bulb itself. I put in an LED and I wonder if that could be a factor

Any thoughts?

It sounds like it might be grounding out somewhere else. I had a similar problem on my Stella where the neutral light would flicker whenever I shifted gears. Turned out to be damaged wiring running from the left switch through the handlebar. Tends to wear out after years of shifting.

Glad to hear you're back in business! The first thing I would check is the brown wire that runs from the neutral switch to the neutral light. If you have a multimeter set it to check continuity. Disconnect the brown and black wire for the selector box switch then connect one lead to the brown wire and the other lead to a good ground connection. You should not have continuity to ground. The only wire that should have continuity to ground is the black wire. It is the ground source for the neutral switch. Basically, your neutral switch completes the ground circuit to the neutral light making it turn on. The white wire at your neutral light provides a positive 12V to the bulb and is keyed on with the ignition switch. So, if the light is staying on in all gears, then I suspect the brown wire is cut somewhere and touching something metal on the frame or both the black and brown wires are touching each other somewhere.

If you don't have multimeter, you can use a 12V test light. Repeat the test except connect the lead from the test light to Positive terminal on the battery and the tip of the probe to the brown wire terminal. If the test light lights up, then your brown wire is shorting to ground.

Good luck!

Hec

This is what I was talking about with the pinch bolts. The slot in the new selector box is too narrow but a file fixed the problem.

Yes, I installed a new gasket.