Modern Vespa

Very much content with my nimble Primera but two up in the mountains here it coúld do with some more grunt.

The few threads here on it are a bit light on info.

Meanwhile any more experience? Especially as the kit now comes with the Malossi Forcemaster 2 to adjust the fuelling:

https://www.sip-scootershop.com/es/product/cilindro-racing-malossi-185-cc-3116669-para-vespa-lx-3v-eu-bis-06-13-taiwan-vietnam-lxv-3v-s-3v-946-3v-primavera-3v-vietnam-125-150ccm-4t-ac-3-ventil_M3116669?usrc=racing%20cilindro%20946

I installed this kit about 3 years and 2000 miles ago. I mainly use the Sprint for my short commute and local transportation, so I don't rack up a lot of miles.

It's a really nice improvement, and combined with lighter 12.5g rollers, has made for a very lively and fun scooter. It pulls very well off the line, still has about the same top speed, has plenty or torque for hills and headwinds, and doesn't exhibit any bad qualities that harm drivability or control smoothness. It's just more Sprint

It's not a huge change from the 155cc cylinder that I replaced, but it's certainly noticeable, and the main difference is that I don't need to spend much time at full throttle anymore. Now, I always have something extra in reserve. To me, this is how the scooter should have felt from the factory.

If you'll be upgrading from the 125cc cylinder, I imagine the difference would be massive!

Thanks, looking forward to it.

Sell it and buy a GTS, you know you want to.

Thanks but no. Horses for courses and where I live thus ride, the lardies are simply literally too much scoot.
350 lbs is too much heavy metal and 24 hp not at all that much beyond 125cc tuning.
Have a look/read on the NSM side in my Andalucía thread. Bar oompf uphill, less is more here.

Looking into upgrading the vario too.
JCosta x 185cc + ECU tune should be the ticket.

Right; going for 185cc and ECU.
Sent SIP a mail about which kit as the info does not list the ´19 3V.

Not sure about the variator yet. Seems a waste of the 185 kit not to. But will take the least light rollers. Those are still lighter than original yet not rev the shit out of its little heart.

ah; different thread reminded me that I already have a fly screen on the way to make the Cw slightly less bad.

The kit is a higher compression, so offers a greater performance boost than just the additional cc.

There's also the ability to purchase different gearing to increase the top speed.

Have a look at this video:

Thank you.
Not looking for top speed though.
Will also keep stock exhaust as that look/sound is easier to live with.

I installed one on my 2018 Sprint earlier this year, and have run about 3000 miles on it since then, including a trip from DC to Ontario and back. I also have a Malossi variator kit and exhaust fitted.

Acceleration is marvelous. Very peppy. Top speed increase was a little disappointing -- maybe 2-3 MPH -- but it sounds like that's not what you're interested in. Some people seem to think the exhaust makes a huge difference, but I am skeptical about this. Like you I don't particularly want a loud scooter, but I find the unmodified Malossi (you can remove a baffle for more noise and allegedly more performance) to not be excessively loud.

I bought mine straight from Malossi as I will not buy anything from SIP.

Installing it was a big job, I'm not going to lie.

Thanks for the feed back.

Yeah, did 4-strokes before and watched the install video so am aware. Thanks for the heads up though.

4 strokes can be ´supercharged´ by tuning the exhaust waves too but not to the same extend as 2 strokes plus muffling changes the game WAY more than in 2 strokes. For road use there is not much to be gained and less still with a cat in the down pipe. A good legal exhaust with sports cat in the down pipe will net you 10% if you are lucky but set one back as much as the cil. kit with variator. Also in mý case over here the stock look in the eyes of the plod is of great value.

btw did your engine have the ECU integrated in the throttle body or not. There are two different part numbers and the difference is in the Malossi Forcemaster (connectors I suppose).
Was trying to order and the imo wrong partnumer only was on stock.

and now for some sacrilege; the air filter

The perspective is that I also have an NSM and the air filter is fine metal gauze only. Now understand that the air/petrol/oil in a two stroke goes through the crank and the mixture lubes the crank et al.
Looking at where the Primavera takes in air and how the tract is, remembering it stays above the piston... why bother with the filter? With my mileage it will not make a jota of difference to wear but it wíll make some difference in the resistance to the 50% more air sucked through.

Mine has a separate ECU mounted behind the legshield.

Much appreciated; same version as mine then.

Ordered from SC:

- Malossi 185cc kit
- Malossi Forcemaster 2
- BGM Pro Variador*




* the actual weights cannot be compared because the rollers move on ramps which are different per brand.
It is good to note that it is the design of this ramp which determines the rev cháracter of the variator. The BGM ramp supposedly increases high speed revs less.
Fingers x-ed.

was reading the user manual and... with accessories top case, windshield, luggage rack et al, 80 km/h should NOT be exceeded.

.... and then there is me who ordered a fly screen to increase max speed

No, seriously, I know it is to a large extend bum covering by Piaggio but it doés have solid reason: These accessories change the oscillatory frequency and the Vespas cán get into speed wobble. Especially a windshield and/or loaded top case.

Seen the OEM Piaggio ´sprint´ solo seat and like it a lot.
Take the grab rail off and it would look a LÓT sleeker.
You think the charming passenger would notice?

If your passenger is male you may want to keep the rail on otherwise he'll be hanging on to you.....unless you're ok with that.

My s150 has the "fast-back solo" seat with a strap. The original owner also added a chrome grab rail which also supports the top case frame.

If the chrome bothers you that much get it blacked out.....

Thank you for the photo. MUCH appreciated! She is charmingly female
Would have no issues with a bloke holding on to me though. With a top case (frame) you have the equivalent of a sissy-bar no!?
I like his thinking btw; the connection adds structural rigidity. I quite like the chrome as it matches other chrome details so no issue with that, but I think the rear line of the scoot is véry nicely sloping and both seat and rail jar with that in my eyes. Practical requirements yes I agree, just like the line of he bodywork.
I have the same issue with the 946 rear: If I´d own one, the little rack would be off the moment it gets home.

see what I mean?!

Both the performance stuff and the wind screen are scheduled to arrive here in the mountains on Monday.

p.s. just received a heads up about the go faster stuff; expected delivery earlier; Fríday!

Just wondering why you went with the BGM vs Malossi Variator kit and why you didn't get the heavier gear drive spring?

I'm considering doing the variator/spring kit to my otherwise stock s150.

The BGM I opted because it meant one stop shipping ánd I hope their design will suit my use.
The way I read the blurp is, the BGM variator characteristic is supposed to be designed to work with the original spring:

´NOTE: A harder counter pressure spring is not necessary and would reduce the performance on a series engine only reduce it due to the higher friction of the V-belt.´

Ok, ok, my engine will be stronger* but furthermore the theory is that having the original contra spring means should hold a higher gear ´better´. Rolling a bit off the throttle should give less ´down shift´.
But I can always go stiffer spring if I feel that needed.

* thus the weights in the kit meant for 150cc will likely be better suited than the ones for 125cc.

Petrus.....thanks for the info. I think I have a better understanding how the Contra spring is designed to work.
The Malossi Variator kit I'm looking at for my Vespa comes with a white Contra spring. Sounds like if you snap off the throttle quickly (with a stiff spring) its almost like down shifting....resulting in better mid-range response(?)

Akin to yes.
The variomatic is all about balance between loads: Load on the primary pulley resulting from revs (centrifugal force on the rollers) and throttle x load on the seconday pulley from road speed/load. The spring in the latter counteracts the load on the belt. The stronger the spring the more pull on the belt is needed to push the pulley apart and ´shift up´.
Momentarily rolling off the throttle will see a strong spring push the pulley tighter = shift down.
A stronger spring logically pushes harder on the belt; more pressure on the sides of it. It increases friction thus some loss of efficiency and increased wear.
What the effects of a change in the forces will be can be sussed out by reason but how much is a matter of trying out.
Remember that the load on the secondary pulley is also a function of rider (passenger) weight, even the bulk of the clothing.
Ergo ... it all depends

Petrus....awesome info!

I also noticed that the "kits" provide rollers that are heavier than the OEM weight. I was under the impression that lighter rollers=quicker acceleration.
I'm guessing that lighter weights with a heavier Contra spring will result in over revving the engine to "gear up". Any thoughts?

You cannot compare roller weights between different variators.

The lowest and highest gear ratio is set/limited by the pulleys.

When my 10,000km service is due I plan on buying a complete Variator kit from a company that has a solid reputation.
The Malossi Variator/Contra spring kit (from ScooterWest)is high on my List. Planning to add an upgraded belt and will consider a new Clutch kit.
I don't know what I'll find when I open her up but once the parts are replaced I'll be good for a few years:)

Thanks again Petrus!

Was thinking of fitting this one too

https://www.sip-scootershop.com/es/product/arbol-de-levas-polini-1694002-para-vespa-lx-s-primavera-sprint-3v-ie-125ccm_P1694002?usrc=camshaft

The kits are in.
Not writing down when fitting is planned so as not to jinx that

Meanwhile trying to figure out if the camshaft fits my production model. If so, it makes sense to fit it same time.
With increased valve opening times, it woúld make sense to fit a better flowing exhaust.

The context is that we are dealing with stock some 6 rear wheel hp meaning every single hp gained is 15%
With a 185cc kit fitted every improvement in flow is húge in respect to the 125cc output.

p.s. nót fitting any of the stickers btw. Those are dead give aways to the plod

Right; the advantage of being a polyglot.
Went back to my tuning roots; the Netherlands. Traditional 4 stroke tuning here starts with swapping a camshaft.
And indeed same thing 4 stroke scooters.

Primavera 125 iGet 3V ABS van '16 tot '20 E4 [ZAPMA1100/ 1101]
Yes! Dit product past op je scooter!


Ordered the camshaft. Again not mentioning eta to avoid jinxing

Camshaft shipped

The fly screen still somewhere on The Channel with compliments to effing Brexit
Don´t know how Amazon wings it because there is no extra (customs/taxes) cost for mé involved but the procedure delay still applies.
Had not paid enough attention or else would have bought from within the EU and not because of the few days delay

The fly screen is in.
I am impressed by the vfm.
Also by the fool resistant pre-assembly

Fitting was a doddle. ´Frutting´ the rubber grommets through the holes in the screen was the most complicated

p.s. yes; charming company will model the screen

In preparation of the engine mod. am looking at the air filter box.

Looks a quite nice design actually.

Will most likely add a hole in the separation between the ´still air´ side and the side under the filter.
Not decided whether I will remove the filter element or not: The front/low side of part #21 will trap stones and larger sand/dirt particles.

Ah btw, over here it costs about 200€ to transfer the vehicle registration. A sports camshaft is about the same

Ok, finally a moment for a photo of the fly screen:

Got all the go-faster stuff in now. crammed it in one box, instructions and all. Kind of to know it´s a handful of horses in it!

The camshaft is surreal diminutive. I know but still rather a difference from the four cylinders I have so far swapped cams of.

Meanwhile... looked at the air intake system again. Imo the bottle neck is in the ´snorkel- which snakes from ahead of the pet carrier, between the side panel and said bucket to a coupling piece onto which the bellows hooks up.
Deleting parts 22 -> 28 -> 21 would imo improve intake air flow.
It should be very easy to verify by simply taking bellows 26 from box 21. Leave out the bucket and take the scoot for a spin.

The crucial ´issue´ with the intake is that the feed is the ambient air pressure. Any drop of pressure / resistance in the inlet tract is power loss.
On the exhaust side the burnt gasses are expelled by a piston moving up. This can manage a way larger pressure difference than this same piston ´sucking´. It can never suck more that the ambient air pressure pushes.

The fly screen is AWESOME!!!
I knów that even the smallest screen makes a huge difference in ´parachute effect´ but ecery time it is to experience.

Anyway, put the Primavera on the table to start on disassembly tomorrow john71 .