Modern Vespa

I hope people are still reading this thread.

Update

Have done about 50 miles now. So I think there's a problem - it starts on a dime, one or two kick overs and it idles well when cold. However, after the first mile or so, the RPMs go way high - it revs on it's own as if I'm holding throttle open. So high that I can take off on 2nd gear from a complete stop. Imagine riding at 30-40 miles an hour, then coming to a stop sign - the revs wouldn't go down. Then after 2-3 more miles, it goes back to normal. It's weird. I've checked the throttle and choke cables and they seem fine and proper.

Thoughts?

air leak or fuel delivery problem, you're going lean if RPM's are taking off

Confirm the carb is torqued but do not over tighten because it can cause it to warp and the slide becomes stuck. Confirm the cylinder is torqued. You could use an aerosol to check for RPM increases around cylinder base and carb but not down the throat obviously while idling. If that doesn't turn up anything it could be one of the main seals maybe the old clutch side that hasn't been replaced.

Torque seems fine, within specs. Didn't do the Aerosol test but I don't see any leaks around the cylinder/head. I'll ride it once or twice more before it gets winterized and then I'll do another proper air leak test.

Mirror

Both seem to be for the left side.

I couldn't adjust the right one and I broke the glass. Don't ask how... Lol.

Do you recommend glass replacement or a whole new set, or just the right one?

Fuel delivery problem most likely. When I tilt the scooter to the right, the RPMs go back to normal. If that's indeed the issue then it's definitely the fuel line

Cool day

Went for another ride today and to do some chores. I've gotten nothing but compliments... people slow down to look at the scooter, at the bank a female teller from inside goes "is that cute scooter yours?"

And towards the end of my ride, a car kept driving behind me and not passing, eventually they lined up with me (riding at about 40mph) and I see 3-4 dudes, I assume Indian since the Bajaj is Indian, smiling at me and recording me on their phones. Passed me but eventually they had to slow down on the left lane as someone in front of them was turning left, so I passed them with vengeance and they were like ecstatic. I'm sure I'm already up on some social media

Finally got to install the new neutral light switch on the selector box. The green light works like a charm!

However, I noticed that couple of times while riding the engine would slip out of gear when on 3rd. Could be going in either direction. Could that be related to the neutral light switch?

Another thing - I have the selector cables very tight, no slack. Does there need to be some slack? What about the clutch? On my other bikes, it's about impossible for the engine to shift without pulling the clutch.

Maybe it's just minor nuances, I can deal with them

Question - where did you get your neutral switch?

https://www.scootermercato.com/Scooter-Parts/Switches/126938_2

Why?

Thanks - my friend Chris's P200 needs one

Highly doubtful the neutral switch is causing that. You want them taught not tight if that makes sense?
The clutch you want about 2mm of handle bar lever travel before the clutch actuating arm actuates. If you remove the pinch bolt you can then push the arm forward with your fingers. There's a spot where it's harder to push. Back off from there a little bit and clamp the pinch bolt down. Then trim with the barrel adjuster to get the 2mm of play at the lever.

This has been brought up before but I have been unable to achieve the above. The slack you're referring to doesn't exist on this engine. I don't know why and I've spent time on this. Basically at this point, the clutch cable is almost loose and still there's no slack. If anything, it goes into gear kind of hard.

I thought you're making sure I bought the right one or something. Funny, as soon as I said it worked like a charm, and it broke. Maybe the vibrations or something but one terminal is loose and it probably doesn't make a good contact inside the unit or something... Oh well, another item on the list for scooter mercato

When I replaced mine it did not work with a P200 neutral switch it was opposite and I can't remember if it was a normally open or normally closed switch but I realized I needed a front brake switch because it was opposite of the neutral type. You might test the neutral with your FRONT brake switch?

Come to think of it, for the Bajaj I believe it's the same as the front brake switch. It's "off" when the switch's pin is pushed in (normal for the brake). My new switch is just faulty...

I think I have fuel starvation issues

Do you know how the engine sounds at high revs when cold? Still high pitch but not smooth?

This is what happened about 3 times today during my 1 hour ride when the engine was hot. All I had to do is wiggle the bike and it got back to normal. Separately, 2 times it sputtered continuously 5-6 times followed by backfire

Does this sound like starvation issue to you guys? I don't like how the fuel hose positions itself when I lower the gas tank but not sure what I can do about it

Just found this thread. That is very cool indeed!

Maybe my question about the fuel starvation was dumb, or people have had enough of this long thread.

My issue was the long fuel line. It was installed by a reputable shop in the area back in 1999 so I didn't bother at first but I followed the advice from another thread (I think was Voodoo) and shortened it so I can barely pull the tank out. No more revving up randomly on its own or the RPMs taking off!

Short of broken right mirror and whimpy battery, this thing is as good as original!

Literally, there hasn't been one time on the road where people beep at me and giving me thumbs up!

I love a happy ending!

That's good to hear, you are absorbing important Vespa trivia and putting it to use, You are learning that while we may not always have the perfect answer to your specific issues, we are good at guessing and sharing what we have learned. Nice to see how much you are enjoying it and that it's worth it to you for all the hassle you've gone through.

OMG you have no idea! I'm going through a messy divorce and have been unemployed for about 4 months now. This thing has kept me sane. Working on it and then riding it with solid concentration... "for those 10 seconds or less I'm free"!

24" on a large frame fuel line is the oft quoted number

Come to think about it, this scooter belonged to a lady who went through a messy divorce. Her husband got a cancer/disability or something and she's ordered by court to basically pay alimony for as long as he lives. 25 years so far. It's unusual... But I guess, this is the scooter's curse! Yet to find out how things turn out for me

This is not something that's said about these scooters very often.

Seriously, though, I'm glad that it's given you something to fill your time and keep you sane through all that.

My favorite scooter experience, hands down, was the time a gentleman was admiring one of my scoots outside a grocery store.

He had tears in his eyes. He said his family had one when he was growing up in Vietnam during the war. "It reminds me of my father," he said.

Have you seen how a cat approaches something weird/unknown? Like looking at it from the left then right kinda of leaning towards it but ready to back off any second?

I had the Bajaj parked in front of Binny's and this guy was doing the same . Asked me what it was and told me that yeah 40+ years ago when he was a kid his uncle owned one in Pakistan and he used to ride on the back...and that he never thought he'd see one in the US. Shook my hand and took some pics of it.

Got a new set of indicator light bulbs - neutral/high-low/speedo lights. And I'm psyched! This is what I ordered:
Ruiandsion 4pcs 3898 BA7S LED Bulbs Warm White DC 6V 2835 4SMD Chipsets LED Bulbs Replacement for Car Interior Instrument Dashboard Warning Lights https://a.co/d/fPuS8Yr

These bulbs are slightly longer but they fit well. 1.5W each vs 5W but about 3 times brighter which is amazing and really good for the battery.

Switched everything over to LED in my Stella including headlight. Everything is running off of DC with factory stator, battery charges to 13.8 volts which is what voltage regulator, regulates too. The factory stators only put out 90-120 watts depending on what you have. Anywhere you can save power it helps.

These are the people I enjoy being approached by. Standard fare "nice moped" lookie loos, less so.

New development...

The scoot has been sitting in my garage since early October last year and just in the last week I noticed a leak. I've been doing some work on it (new brake shoes, repainting the wheels) so I know it's recent.

About a month ago we had the coldest weather for the season - single digits outside and last week the temperatures were in upper 50s. That temperature variation makes me think it's the reason for the leak.

Please convince me that I don't need to take the engine off and redo the gasket...

they leak. it's just what they do. unless you go nuts with sealant on everything, I always expect a little seepage and weepage.

whether you wanna split the cases and make another run at it is call as to how much it bugs you and *where* it's actually leaking from. so I'd deduce the source of the leak first before dreading a split.

Insanity Wolf says:

Looks like here right?

You don't need to go crazy using sealant… the thinnest layer is enough.

The gasket will do most of the heavy lifting.

That's where it accumulates but the leak may come from elsewhere.

So I'm ready for that 2x4 now - back last summer after doing an air leak test and ruining 2 gaskets, I decided to go with Permatex Gasket Maker/Sealant that had high ratings and was designed/recommend for 2t engines. Someone will say now "we told you so", and I deserve it.

1980 Bajaj Barnfind (Post 2626269)

At the end of the day it will bug me so sooner or later I'll split the cases and redo it

Jab your finger into that goo and give it a sniff. Is it gear oil or gas+2t. A combination thereof?. I seem to always get a little leakage from the carb box. Also check the cylinder base and exhaust stub. The drip happens at the lowest point of the engine. I always seem to have a slight 2t/petrol sheen on the back of my engine case. I give it a wipe down every coupla rides so crud doesn't stick to it. I consider it normal.

Will do and I also seem to have that sheen on the back of my engine case.

Just taken apart some cases where the gasket didn't have any sealant.

Leaked the location where it's accumulated on yours.

Gasket just didn't hold up.

There was only 100ml of gearbox oil left.

I made the mistake of first running my hand over the bottom of the engine case when I first noticed the leak - habit, so it's hard to tell exactly but this morning looking at it again, I think you're right about the location.

Imagine, I don't even have a gasket... Definitely gear oil, kind of burnt too, who knows if normal I mean it's been like 500 miles since I got it running

Long running thread, I know... I think I asked this question last year...

Do these scoots burn oil?

I've only put around 400 miles since I rebuilt the engine but this doesn't seem normal to me.

Yesterday I ran the engine for 10 minutes in the garage after it had been sitting for 4 months and sure enough, it dripped "spooge" (I think that's what this is called) :