Modern Vespa

Howdy All,

I am new to the forum but have been lurking about for a couple of months. You guys are great and there is vast knowledge base here!

I am in the process of completely redoing my 1980 P125X American Spec. At the time of this post the scooter is completely torn down and almost ready for sandblasting and powder coating and paint.

History of the scooter: I purchased it in Sept 2021 with 5,400 Miles on it. It ran decent and started within 1 or 2 kicks. The engine was pretty grimmey with caked on oil on the outside and caked on oil found behind the flywheel. So it was in need of shaft seals. The scooter would top out at 45MPH (GPS Verified). The speedo is reading about 8-10 MPH low. The ride is very good with no rattles or shakes or weird vibrations. I don't care for the blue color so that will be changed! It has the BBQ rack with the "Vespa" embossed rear seatback pad. That will come in handy for two up riding.

Plans for the Scooter:
Body: I have already welded up the mounting holes in the frame for the US Spec Taillight and have pre fitted a Piaggio European taillight I have also welded up the mounting holes for the side reflectors on the fender (mudguard).

New Color Scheme: I think I will go with an "Italian Flag Color Scheme" Green, White and Red on the leg shield with Red and Green Cowls . The frame and horn cover will be white.

Speedo: I have a new SIP 2.0 digital speedo to replace the original. I will also be installing a new SIP Fast Flow fuel tap to compliment the speedo which will give me a warning of low fuel displayed on the Speedo. In addition I will be utilizing the SIP cylinder head temperature sensor as well. Since the SIP 2.0 Speedo does not have a "Neutral" indicator light, I have installed and pre fitted a small green LED just below the high beam indicator light on the steering top panel.

Suspension: New front and rear shocks and rubber bushings will be installed, new wheel and fork bearing/bearing races will be installed. New brake shoes will be installed.

Electrical: The original wiring harness is excellent shape. The only wires that needed replacing are the stator wires and the 6" green kill wire at the engine. The green wire in the harness and in the handlebar housing is in mint condition! All turn signals will be replaced with the chrome bodied clear lens units.

Controls: New SIP teflon lined cables will be installed.

Engine: Here's where I need some guidance. I will be replacing all seals, bearings etc. The gears look good. I will be replacing the shifting cross and the kick start gear. I will be replacing the gear shim with a 2.5mm one. New clutch plates will be installed too.
I have a Mazzuchelli flowed - stroked crank. I also have a P150X Cylinder that's been bored to second oversize 58.2MM. I have a new Piston/Rings and head to match the cylinder. I also have a new SI 24 Carb and air filter to replace the SI 20. I believe it has a 115 main jet in it. I have a SIP Road 2.0 Exhaust with the twin pipes for it too. Will this set up work? I would like the scooter to cruise along between 55-60 MPH. Most of the time will be riding around at speed less that 40 MPH but If I venture into town I will need to take a highway for about 10 miles. That's why I would like a bit more speed.

Sorry for the long post! Any help is greatly appreciated!

Here are some pics of the project!

Hec

Will be eagerly following along your project. It almost looks like mine and I like the blue color. Mine will be a "utility bike" so I'll be leaving cosmetic scratches and miscolored panels as-is on mine.

Welcome Hec!

That bike is beautiful.Looks perfectly straight.

One thing you might want to consider if you're building a faster engine is the gearing. The p125s have lower gearing than the 200.

Malossi has a gear cluster kit that makes the gearing a bit taller.

https://www.scooterwest.com/malossi-gear-kit-23-64-for-p125-150cc-m673730.html

Welcome to MV Hec - I gotta say, that paint looks nice!

I would've suggested that you take the engine apart FIRST, and ride it for a year (without the blown seal). But alas, this is your first post, and the scoot is already stripped.

It looks like you've got it figured out. You may want to go with a Malossi 177 kit vs the 150. I don't have any experience with them, but if you're putting in a new crank. I'm sure someone else with experience with your setup will comment at some point.

Good luck with the project. I'll be following along!

Thanks everyone!
Here are some pics of the engine stand and Vespa Stand I built to help me with this project. They are copies of stands sold overseas with my own improvements. I needed them and didn't want to spend a lot and wait for shipping to the U.S. so I made my own!


Hec

Welcome to the forum. Beautiful original blue P125x that you have. I'll give you my honest and humble opinion. I wouldn't have done the change of color paint, you have(had) an excellent condition original paint that is not too common and holds its value very well. The new color theme will be great for you because that is your personal choice and you like it but if you ever need to sell it you can count out a lot of potencial buyers because custom paint is not everyones particular cup of tea and your new paint theme is not an exception.

If the current engine is able to pull 45 mph with bad seals you might be able to pull maybe another 5 MPH with the 150cc top end once the new seals are installed. I tested the speed on new PX and LML 150 engines and they are in the 50-52 mph GPS top speed.

If you decide to go with a cylinder kit for more top end I would recommend Malossi or polini although BGM is also great. I purchased a Malossi 166cc and a 177cc and both netted me roughly 15 mph on the top end and they were $249.

You seem like a talented/skilled person, I love the engine mount.

Hec,

Where in Omaha are you? You wouldn't happen to have the secret recipe that Casey's uses on their breakfast pizzas?

I definitely would get any kind of kit- Pinasco, Polini, Malossi 177. It's night and day difference with something other than stock installed.

If money is no issue, definitely do the clutch cog/primary swap as well.

Hey welcome!

Word of advice the green wire will be bad elsewhere sooner rather than later. Replace the harness. Full stop. It's a small expense and easy with the bike in pieces. Trust me.


That blue paint was gorgeous!! Sad to see it go but looking forward to watching your project.


Plus 1 on the 177cc kit if you can.

Again welcome!

I am glad that I am not the only nor the last person to say it...

the limitation to your top speed is going to be gearing. the 24 and the pipe will net you a little in that it'll breathe better, but don't expect a world beater. it'll do 55 though.

so if you've got the coin, do the gears now.

do the harness while it's all apart, you'll be glad you did.

while painting it wouldn't be my choice, it's your bike and you're not asking me to pay for it. but I look forward to pics of the project.

Put me on the list for not using the iron 150 cylinder - opting for an aluminum kit.
1. Yes - more power.
2. Less likely to seize due to heat
2. More CC's = power available at lower RPM

Highly recommend the BGM for piug and play joy.
Will be excellent for riding around town and your hwy needs.

Good luck and keep us posted.
-CM

Get a new cylinder to help get your top sustained cruising speed where you want it.

Thanks again everyone! The blue paint on the scoot looks good from 20 feet away. It's got plenty of scratches and a few minor dings. As for the engine, I didn't want to open up the cases by grinding on them. That's why I opted for the P150X top end.

Here is a pic of my inspiration. It's not a done deal yet!

Charlieman22

I like your leaner sidecar pictured in your avatar! Here is a pick of a mini bike I built for my daughter. She's still driving it and giving our dog rides!


Hec

You can bolt on a VMC 177 without porting, like I did. It'll feel great with your Road 2 and a 23 tooth BGM clutch.

VMC 177 pnp porting on a PX -- do I have the meat?

If you want the most power, you've got to open up the cases some BUT Any kit just bolted on, will still give you better performance than a stock 150 top end. It's that night and day difference!!

If you haven't already, plan on buying some extra main jets. 120-130 range. The 115 that came with the carb won't cut it in the hot summers.

IMO Dont touch that paint, its original and gives it the patina consistent with its age. Resprayed scoots are ten a penny, the one you've got don't come along that easy in that condition; its very good condition and that blue is great. it really doesn't look that bad, bit of touch up paint, and polish and dent dolly the dinks, jobs a good one. My PX is original black, its gone matt in places after all the years of sunlight, weather and use and quite frankly it would look wrong spraying it. Ive got a DR177, cosa clutch as standard, 24mm spaco dell orto and a road 2.0 in mine, not a thrill machine but pulls 65mph on GPS, does 90mpg and all these things were bolt on. Yes I could get a more modern kit with greater oomph, but its very reliable and starts all day as it should and i dont fear it blowing up by being overtuned.

Ray8

Thank you for sharing your experiences with the VMC177 kit. Looks like that is what I am exactly looking for! I see there are a few options for that kit. Can you tell me which one you used, or provide a link to it?

Hec

Big fan of the blue too.

This is the kit to go with your longstroke crank ( if 110 conrod). And would be fine on stock inlet port and case transfers, as you don't want to grind.
https://www.sip-scootershop.com/en/product/racing-cylinder-vmc-crono-187-cc_84140500

As mentioned, it will need an up gear kit. 22/68 as a minimum but a straight cut version 23/64 would unstress the crank bearing. Going to need a clutch upgrade. Change the whole thing to a Cosa while at it. This is the last clutch you'll ever buy. Cog will need to match your primary gear choice. 23 helical comes in two different versions be careful if going that way.
https://www.sip-scootershop.com/en/product/clutch-sip-cosa-2-ultrastrong_93404300

Jack 221,

My crankshaft has a 105 mm con rod. This is it.

https://www.sip-scootershop.com/en/product/long-stroke-crankshaft-mazzucchelli-k2d_45046000?q=Long%20Stroke%20Crankshaft

I don't think the kit you recommended will work. 187 cc's? I guess the only thing better than cubic centimeters is cubic meters!



Hec

To go from that factory blue to those Italian theme colors should be against the law. Your scooter and good luck.

105 rod has many options if the casing is cut.
https://www.sip-scootershop.com/en/product/racing-cylinder-malossi-mhr-187-cc_31173610
This is the fastest, most powerful and about the only one that will bolt on with no grinding at all and still go ok.

Thanks everyone for the cylinder kit suggestions. I have a lot of options to consider. I am currently fitting the right side outer floor strip. The original was bent due to an impact on the right floorboard with something in the past. I have straightened out metal but the old aluminum floor strip needs replacing. So I bought a kit from SIP since I need new rubber too. I fitted the outside strip and all is good!
I also have been messing around with my top case mounting on the BBQ rack. I need to order three 1/2" wide x 12" long black leather straps used to secure the case to the front and rear of the BBQ rack to keep it from shifting front to back. The two 6" long straps under neath are fine and keep it from shifting side to side. I think the top case shouldn't contact the backrest frame to prevent getting nasty wear marks on it. So I'm trying to keep it off the rear backrest frame. I found a source for straps that look like the originals.

https://www.barefootleather.co.uk/leather-cat-basket-bicycle-hamper-picnic-straps/.5inch-leather-straps/BLcatD

Hec

Everyone has their own style...
The engine stand is great.
I love the scooter stand too.
Nice job.

I think the Italian paint job will be a total hit.
Expect to have people stop you and want to talk to you about it.
Is it original to the scoot? Not even a little.
But in fairness - its not like you are taking a low series number 1946 Vespa 98 and adding a sidecar or something... 🙂
Oh - and the black leather bag looks gorgeous too.

With time - most of us come to appreciate more and more the original colors and details.
With that said - there are all sorts on here - from bare metal racer - to pink with a fog horn -
and in my eye - they all look great in their own way.

Keep the blue, it's absolutely gorgeous.

as above, bolt on the VMC 177.

As you can see - there are plenty of opinions.
Here is my understanding of your options.
- VMC: pretty much everyone that uses them loves them. They are the least expensive normally. That said - they tend to have lower quality control in their finishing process. Plenty of documentation on that. The one I have was fine. But... the chamfers on the ports looked like a blind man with a Dremel at the end of a long stick - had done the work. The bolts and nuts needed threads chased. There were no instructions on ring gap or torque in the box. Bottom line - generally great value for money - plug and play solution without case split if you want, just be ware you may need to clean things up.
- BGM - great value for German made product. Good quality. bit more expensive than VMC. Bottom line - generally great value for money also. Both this and VMC are plenty torquey
- Malossi - MHR - likely the best performance model. Nice quality. Most expensive. Aggressive transfer port shapes that just back at the cylinder studs. Not sure they plug and play as well? Bottom line - Top cost and probably the sportiest of the options.

Easy way to be sure of the fit with your cases on any above: order a base gasket for each and slide it on your studs to see their match to your cases. Pay attention to sealing area all the way around to ensure you have at least 2mm+ min at all points.

BTW - saw the sidecar mini bike. chuckled. thats pretty awesome. My avatar should probably get updated. That was shot on day one test run. Since then - it's been farm fed whole milk and wheaties.

Is the BGM cylinder really made in Germany? BGM, as far as i know, is a designer and outsources all production. The manufacturer of the cylinder could be in Germany, but i have never seen it in print--doubt they would tip their hand either.

the quality of the VMC is on par with the BGM; there is no doubt there:

https://www.sip-scootershop.com/en/product/racing-cylinder-vmc-stelvio-177-cc_84140900

https://www.scooter-center.com/en/cylinder-bgm-pro-177/187-cc-also-for-elestart/electric-starter-vespa-px125-px150-cosa125/150-gtr125-ts125-sprint-veloce-vlb1t-0150001-lml-star/stella-125/150-motovespa-px125-iris-99m-px150-iris-75m-125-cl-9cl-150-cl-9nc-bgm1770ne?number=BGM1770NE

I would also say the VMC is more expensive than the BGM, but you are looking at $20.00 which is not much at all.

As time goes by, the distinction between pre P and P series bikes will gradually fade. I like original too, especially that blue, but it's your bike and you have no obligation to preserve it as a rolling museum piece. Enjoy it as you see fit. Good luck with your engine build.

Howdy All,

I opened up my new carb and here is the Jet details. Looks like I will need bigger Jets for a 177 Kit.

Hec

I'm on team blue.

The color is called Blu Marina 275, and available as an exact match (with that code) through PPG in the USA.

Also sometimes Navy Blue or "Marine Blue" (Maxmeyer 1.298.7275)

https://www.vespafarben.de/suchfilter/blu-marina-275/

That's such a great color. It was used on some p200s/p125s imported to the US, but least common color on those.

That's just me, though. I'm obsessive about original details.

Does this look like the same color? If so, I can tick another question off the list. Yes, I am biased.

Geez another vote for blue? This is turning into a kind of intervention! This was second choice for paint!




Ha! Just kidding!

Hec

I dare ya!

That is hideous. And not in a compelling way.

*snork*
You are gonna fit in here just fine.
You do you. Whether blue or Neapolitan, I'm pulling for ya!

Maybe on the main jet. Others can chime in on the others as I'm far from an expert on jetting. However I run the aluminum VMC177 with a 116 main with a Polini box exhaust. I have a BE3 mixer and 60/160 pilot

Yeah I'm in for blue too. Your scooter but that original paint looks like an easy clean up.

It looks pretty close! If that's original paint, then most likely yes.

US market P's came in only two blues I've ever seen. China Blue and Marine Blue. There were a lot more in China Blue.

actually, I kinda prefer this paint scheme over the Italian flag one.

just remember, they're only original once.

(Letter Kenny intonations)
Personally - I think this is used car lot close out special blue.

There are some super nice blues that Vespa used, shame this isn't one of them, blue I'd say.

Some perfectly good village is missing their idiot (painter), blue, if you ask me.

Dealer didn't have any scoots left on the lot and begged me to take it blue, I'm pert-near sure.

If it were my balls and they went that color blue, I'd paint em like an Italian flag blue.

Hec's shade of blue is the single most boring color piagio offered that scoot in - if your not counting the maroon. Don't get me started on maroon.

Hey, hey, hey now... Maroon is classy....

Hmmm. Note jump suit. Note flannel.