Modern Vespa

I have what I believe is an all original 1974 Super with just over 2,700 miles on it. Everything works except one indicator. Runs OK but is really slow. Asking for opinions on whether I should:

1. Leave it stock and grow to love the sluggishness
2. Do a small upgrade, such as carb and exhaust and see what happens
3. Put a new jug on it, such as a Pinasco 177, with 2 above

No projects in the works so itchin a bit and wrenches are callin'.

But, purists would say it's only original once.

Thoughts?

Hey Chatis,

Beautiful scooter! If it was mine? New cylinder kit and fresh rebuild as well as flow the carb/box/inlet while you're doing the rebuild.

I think of it this way: I want to keep up with traffic and if I plan on riding it and not have it as a museum piece, might as well update it to run a bit faster.

If your concern is originality box up and label any parts you take off and store them. Unless you go wild you can always put it back the way it was with the proper parts or include the original parts when you sell.

a 20/20 carb alone may help. A kit made for the 2 port cases would mean zero mods to the case. agree with keeping any stock parts you take off.

OR....

Swap the whole motor and go hog wild. Keep the original totally original including unsplit

Beautiful Super, Chatis.

Been in your shoes, and agree with the others. You can bolt on some mods and make it a better rider without affecting the originality. A 20/20 carb and better exhaust alone will add some punch... a bolted on Pinasco or Polini will really wake it up. Keep the original parts in a box for the next owner.

I'm not sure when Piaggio started to use the 3 port cases in the Super (same as Sprint Veloce but with the 2 port cylinder). My '76 is a 3 port, so I put the original 2 port cylinder, head and piston into a box for safe keeping, with the 6v stator, the flywheel and coil, and then used a 3 port 177 kit (BGM in my case) and a 12v electronic ignition. You can choose between a 20/20 or 24/24 (if you open the inlet somewhat)

An original 150 Super motor is dangerously slow IMHO

Swa45, did your '76 come with the muffler attached to the swing arm with a thru bolt to a captive nut in the double tab bracket or a bolt into a tapped hole thru a single muffler tab? Interesting that they shipped 2 port motors on 3 port blocks and I'd like to know if ALL 3 port blocks have the thru bolt, it's such an easy way to tell a 2 from a 3 just looking on the outside of the motor.


And as noted the 20/20 carb, a good box exhaust and a modern plug and play top end kit will get the job done nicely with gearing to match, usually a problem if you swap motors for something hotter and converted to 8".

BTW, your paint looks great, lovely color.

Gorgeous bike!!!

20/20 carb.
Pinasco 177 top end (or similar).
Big box exhaust.

Bobs your uncle.

I wouldn't go Big Box rolling on 8's. To easy to ground it out.

SIP Road is good to go, though, and would be my choice.

Fair.

Lots of great comments - thanks. Whatever I do I do not want to split the cases.

I think I will do this incrementally. Ill order an injected 20/20 carb and a SIP road exhaust. Not looking for a rocket here, just for better speed and acceleration. If this works I am set. If I decide I need more ill put on a kit. I would need the carb and the pipe for the kit anyway.

Not thinking about doing anything with ignition. But that may be a consideration at some point. KISS!

The three things to touch are the cylinder, carb, and exhaust...leave the rest be and don't try to do too much on 8" wheels. That thing is nice.

We have twin scoots! Yes to everyone's comments above, I have the 20/20, pinasco and SIP Road on my Blue and it's a lively ride.

Hello V oodoo, mine does have a through bolt for the exhaust, just like a P series. I guess it's the same case as a Sprint Veloce of the same era.

I think a Polini BOX would suit you better. Loses a bit to the SIP Road at high rpms but it has lots of torque down low and better ground clearance.

Going non autolube with a 30mm carb and not altering anything is an option.
Quattrini M1xL
Reed induction direct into the cylinder and blank off the rotary inlet.
Will go on 2 port or 3 port engine.
https://www.scooter-center.com/en/cylinder-quattrini-m1xl-172-ccm-3-ports-vespa-px125-px150-cosa125-cosa150-lml-star-125/150-stella-125/150-7670371

Yaaaassssssss....it's the solution to the problem I never knew I had...

I even have an actual Keihin 30mm PWK just lying around.

Just put a Polini box on a friend's 8" wheeled 75 Super. Nice torque, very spunky.

Ground clearance is about the same as BGM. With Heidenau K75's, not bad at all.

However, it DOES NOT fit with a centerstand. We went with a side stand.

Will the internals be able to stand up to the additional horsepower?

I had a VHSH30 lying around, so I brought this kit. Who says it's addictive.

If it's in good condition and runs ok now. It will take it. Obviously things will wear out quicker if ridden hard but for general use and the occasional thrash it will be fine. Setting up correctly is the key to reliably.
Would make that old crate into quite some sleeper.

lol ... depends what you mean by "stand up to". A beefier clutch would be prudent with that set up.

I have ordered the 20/20 injected carb. Are there "less expensive" options on the exhaust. Will an economy 150 exhaust work. Why does a economy 200 exhaust not work? I don't have a 200 and don't know if there is a difference between the 150 and 200 exhaust. My ignorance.

I think a Quattrini M1xL is going to be on the cards for one of my Stella's. I am curious.

The 200 exhaust stub comes out at a different angle and is larger. so no.

I'd take it a step at a time and roll back when you go a step too far. The stock exhaust on the 150 super is better than what was on the VBB and has the same ground clearance. the exhaust is the first thing to ground when you stray from stock. For me the ground clearance means a lot when humiliating sports bikes.

Carb has arrived....

More advice needed. Was thinking that I would start with this jetting setup:

Main - 160AC/BE3/102
Idle - 55/160

Essentially the same as a PX 150.

Anything I should know about that I don't. Again, a 74 Super 150.

What was the issue with the center stand and the Polini box?
Mine is one of the stops hits the pipe. Got the SIP side stand. Going to move that stop so it hits elsewhere against that new plate and away from the pipe.
Let's see how that goes...
https://www.sip-scootershop.com/en/product/side-stand-sip-76_75085300?q=side%20stand

Same issue. Centerstand fouled on the header. We went with a different side stand, one that attaches to the center engine bolt. Nice and sturdy.

https://www.sip-scootershop.com/en/product/side-stand-sip_75192000?q=side%20stand

I have installed it and it started right up. No adjustments of anything. Idles perfect.

Has good low end power on a very short ride BUT it sort of stalls on power as the throttle opens. Best to describe as stops accelerating. It does not hunt. I don't think this bogging.

So, what does this mean? Not enough fuel? Should I go to a 107? Too much fuel?

I think that only one thing should be changed at a time but there are three things that can be changed on the main. Let me know what you think...

When starting from an unknown point always try a larger jet first. If that makes it worse then try smaller

Great advice! I went to the biggest main jet I had, 106. And it made a big and positive difference. But there is still some hesitation so I think I need to go bigger. They will be ordered. Should I have any concerns? Rich? Lean? And yes, from the few rides I have now done I believe that this is also true. Just needed the bigger carb to feel like it can keep up.

Quite pleased!

Thanks OopsClunkThud ("OCT")

I'm diggin this side stand....

Definitely more ballsy than the other style side stand. I'll start another thread about mine.

Me too, it's sturdy & stable, and a breeze to install. Highly recommend it.

This carb setup thing if flummoxing! The carb stack that I have in the super is so similar to both my Stella and the Allstate running a 177. The only difference between the three is the main jet. On my VBB (with a LML transplant) the stack is quite different.

So, since there are so many variations my first question is are there any similarities that can be accomplished with different combinations. For example, can a 55/160 idle with a 160 BE3 105 be equivalent to a 38/120 idle with a 140 E3 98?? The interactive aspects of the circuits have to have more than one solution for an optimal setting.

Also curious to me is the fact that three engines of different generations and capacities have almost the same stack. The fuel consumption is a function of the idle jet and the main jet. Having a richer idle circuit and a leaner main circuit could use the same amount of fuel as a lean idle circuit and a rich main circuit. How this relates to setting I don't understand. For a scooterist like me, that is more concerned about reliability and longevity of the engine than overall performance (HP), I would think that leaning towards richness is preferred.

However at the heart of it is how the thing runs, sounds and idles. If it starts easily, idles smoothly and runs well through the full throttle I think you are close enough and you are set.

What you read on this forum and others suggests that this is not OK, and that you may seize the engine or risk it coking up completely. All scary and confusing.

To close this off....

Carb Setup I will be riding for a while

55/160 Idle - Relatively Rich
160 BE1 100 Stack

Idles well, pulls consistently through entire rev range.

Original exhaust.

Actually, that wasn't good. More playing tomorrow.

140 BE3 98
160 30 96

Its good on low end. I think it is being flooded on WOT.

Having fun on this thread all by myself...

Ended up with main being 140 BE3 96. It is amazing to me how such a small difference in the main jet size makes such a big difference on the performance.

Now I have not chopped but the plug is chocolate brown. And the revs are smooth all the way up to what I consider close to redline.

I have learned that bogging is not only caused by running too lean. Bogging can also happen because you are running too rich. It all has to do with the ratio of air to fuel.

Also, not sure if what I experienced is truly bogging. What I was experiencing is that the scooter was no longer accelerating and the engine was running like crap at high revs.

I'm glad you got the jetting sorted Chatis. Are you running the stock crank and the stock 150cc setup?

Yes QA. This is a bone stock original Super. All I have done (so far) is change the carb from a 20/15 to a 20/20. I did buy a Polini exhaust for it but that may get allocated to another scoot. Its running quite well now.