Modern Vespa

Yeah that's the one. Gotta track one down and see if that solves it. Otherwise I'll probably just pull the oiler out and go premix I guess.

If you can't find a Piaggio washer, maybe Mcmaster has one? Think about replacing both of the #28 O rings.

I found a ton of swarf at the bottom of the box where the #27 gear pieces both fit in my box. It caused 2t oil leak issues on one of my scooters. Cleaning out the swarf and replacing the two O rings solved the issue.

Welp I tried to clean the pump and reassembled it and still leaking. So out she comes.

Already removed the tank and everything then removed the pump shaft thingy that sits in the engine case and noticed there was some swarf on the shaft which is probably what the problem was. I didn't clean that off when I did the pump itself. See the picture below for the evidence of the leak coming from where that shaft sits in the case.

I may go back to auto lube in the future so just gonna put the whole set up on the shelf for now as I'm sick of the leak and don't wanna put it all back together just to keep leaking. I'm too annoyed to deal with that for now. So premix it'll be.

So the new adventure begins, removing what needs to come out for the switch. What all do I gotta do? Plan was to get a new carb, carb box and gaskets and one of those blocking pieces for where that shaft goes. Do I need to remove anything else?

Is that pic distortion or are the right stud threads shot?
Oil leak through the gasket

There's no way to torque the box (or anything) correctly without clean threads.

If not pic distortion, double-nut remove it, see if you can clean them, or this next step:
https://www.scootermercato.com/Scooter-Parts/Hardware/S-00521

*Check that the carb isn't warped.

Pic distortion and shadows. They're pretty clean but I'll pull them and have a go with them. Carb is not warped. Carb box on the other hand very well may be.
Blue loc tite on the threads when I put them back in?

those threads looks good, I'd leave them in place. Yes on the blue loctite if ya do pull em.

I would bet your carb box is warped. Lap the bottom and see how it does

^^
What a difference a camera angle makes.

Had a thought, before I spend money on the problem, why not give it one last chance?

So I lapped the carb box, double checked the carb base, cleaned all of the pump parts again, this time including the pump spindle thing. Then reattached everything. Last chance bucko, it's work now or live on a shelf, up to you oil pump.

Can't test till next week though. When I was cleaning the brake drum and installing new pads, I broke a weld holding one of the studs on the carrier somehow. Noticed when I installed it and could get the wheel to spin, the stud backing was hitting the case. Getting that fixed on Monday when my friend is at his shop and can get it done.

Didn't even have to go for a ride to know it's still leaking. So out it comes.

I think it's the carb casing being warped. Either way it'll be easier to have both scoots using the same premix gas so that's what we'll do.

One day I may grab an injected carb box. Today is not that day though. Too annoyed with it currently.

Just ordered a carb, carb box and block off cap. So once that arrives I'll get back to this bike.

Planning for the future when I need to crack open the case now. Looking for a short 4th gear and am looking for advice as to if this one below will work with the EFL drivetrain?

https://www.sip-scootershop.com/en/product/gear-cog-36-teeth-piaggio-4th-gear-223229-2232294-for-vespa-px125-e-lusso-2-98-my-11-t5-cosa-125_22322900

Yes, that's the correct short 4th for an EFL transmission.

Excellent, thank you!

I missed it back in July. You don't need a new carb box or carb. Fill the oil channel in the box with RTV and use a gasket without the hole on the existing carb. And of course the block off cap was a must.

Had a run with this bad lady and when I got home I noticed my tail light was no operable. So I'm digging into it now.

Red wire at the brake switch has connectivity with ground.
Blue wire does not.

Red Yellow and Black at the light housing have connectivity with ground and red and yellow have connectivity with each other.

All of my grounds are grounded to the frame and are good when I check each individual one. Headlight, CDI, tail light and regulator.

Any help figuring out what is going on would be much welcomed!

Harness was new and everything ran fine for awhile. Till it decided it didn't want to anymore. Bulbs are also new. 5w for the tail and 10w for the brake. Any ideas?

Red and yellow at the taillight don't have connectivity to ground with the bulbs removed, right?

Just checked and they do have connectivity with ground with the bulbs removed as well.

Okay, wow. I was hoping it was bulb filament continuity.
So both are shorting to ground somewhere
New harness. Worked until they didn't.
Kinda stumped.
Did you do any work like pull the tank between when it worked and didn't?

Maybe look for damaged sheathing on the wiring to the taillight where they pass through the chassis
Brake light circuit doesn't go through the headset, so guessing the shorts have to be from under the tank to the tail.

Yeah that was my confusion too. Tried to hook a battery up to trouble shoot. Apparently either both batteries are toast or my battery tender doesn't work. Had them plugged in charging for 2 days and neither have any juice. I'll double/triple check the brake wires from the switch to the housing and see if I see anything amiss.

If you had a short, you blew the fuse on the battery.

Unless you're not running a fuse, in which case be sure to capture and post the video of when the electrical fire starts.

No batteries over here my man.

As your (I'm assuming) headlight and horn work, you don't need a battery to troubleshoot.

Disconnect red and yellow at the taillight and test again for continuity to ground.
If they do, disconnect red at the brake switch and try it again.
Those would be my next steps, fwiw.

Red does not have ground connectivity to ground
Yellow does

With red disconnected from the brake switch I get the same results…

Got it.
Sorry, forgot:
Do you have a running headlight bulb?
That will get yellow at the tail to beep to ground.

Where are those straws
Damn, way over there. Give me a sec...
You have the two-festoon taillight, right?
They have plastic insulators that insulate the yellow and red connectors from ground.
Do they look like they're doing their job?

Sorry so late to the party again…
Yes the headlight worked. Tank is out so I haven't kicked her over to check again but it was working fine when parked… lol seriously I swear!
Two festoon correct. Plastic insulators are there and doing their thing from what I can tell.

Swapped the bulbs and put the tank back in and pulled her off the lift to get near the door to kick her over to check the lights again. Why's there drips under me? Also why does it smell like gas? These two things couldn't possibly be related could they? …

So after cleaning all the gas off the floor and out of the tunnel and drying it out with a fan for 2 days to remove the smell and then sweeping up the absorbant stuff I finally hooked up the gas line and tried again.

Headlight works. Horn works. No tail or brake light though. Next I'm going to check the voltages with the bike running and revving. Can't do that till Monday though.

Had a second today to finally get the voltage check.

And we've got next to nothing. 0.222 volts while reving. About the same idling. Both were well under 1 anyways. It jumped around a bunch but never went above .222

Where do I go from here friends?

Neither of the taillights work, right?
Does black at the taillight continuity-beep to chassis ground?

Yes and yes. Both lights out and ground has continuity with the chassis.

I'm so confused on what is happening and how to fix it.

Ohm test black to chassis ground, like a flywheel cover bolt.

Your brake and running lights are separate circuits. The only common wire is black.

First test was ohm test black to frame
Second was black to flywheel cover bolt
Third was black to CDI bracket ground

?feature=shared

Jumps around a bunch with the first test then is less jumpy with the second two.

That's good ground.
I can't think of another way both could go out at the same time

Some quick things to try for clues:
Two festoon bulbs, right? Continuity test the bulbs end to end.
Continuity test yellow and red to that flywheel bolt without bulbs --including the running headlight bulb (the small one) if you have one.
Run the engine and voltage test yellow, and red with the brake depressed, to that bolt.

Festoon bulbs yes. Continuity between the ends.
Test red continuity to flywheel sans bulb no beep
Test yellow to flywheel sans bulb, beep.
This bike doesn't have the pilot bulb, has the headlight is turned on bulb though. That one is silent with ground as well.

With the bike running I get the following:

No probes hooked up ~ 0.035-0.045 ish volts

Yellow wire to flywheel cover bolt with bulb ~ 0.053
Red with bulb ~ 0.052

Yellow without bulb ~ 0.03
Red without bulb 1.3v


Something's doing something or not doing something more appropriately.

What's the output of the stator?? Blue to black, AC, loom disconnected…

Ohm test yellow to black no bulbs.

13-14volts at idle

80+ fully revved out.

2.5ohms rock steady.

Probably speedo bulb resistance. I forgot that's in the circuit.
Disconnect yellow to the taillight at the headset and test again, yellow to black.
Should be OL/no beep.

Whoops forgot to press the brake pedal when I did this one.
Yellow gets 0.012
Red gets 0.003

Whoops

No ohm or continuity with black

I tested the ohm's with the bulb in and it was 3.9 not sure if that helps or is useless.