Modern Vespa

Hi,
I'm planning an everyday street use build and my big question here is; do I go for an aluminum or cast cylinder?

Starting with a Primavera ET3 so I already have electronic ignition.

Suggested build;
* Polini 130 cylinder kit - Alu or Cast iron
Looking to choose between the Polini Race 130 (cast cylinder) and the Polini 130 EVO (alu cylinder). Both have alu heads.

* 24mm phb carb
* Mazzy race crank
* Short 4th DRT christmas tree
* XL2 clutch
* No mod to flywheel
* Keeping SIP Road banana

If I can afford both, what are the pro's and cons?
I'd hate to loose the normal smallframe feeling with a low idle and typical sound.

If you're keeping the banana I'd just go cast iron with the new style cylinderhead.

Fonte more strong in time
Aluminium more performance but more fragil
The best for et3 polini doble admission with pipe in 2 it's fonte
But strong and perf

I had an primavera t3 champion of Spain in 70/71/72
In this configuration whit more modif in carter and an rotor very light not electronic
A rocket !...

I would definitely do the cast iron because it's suited for the tuning of your exhaust.

On a side note, you might be able to run that stock cluch with a stronger spring.
I have a similar set up ET3 ignition, mazzy crank, Malossi 135 on a SIP banana and my clutch has held up fine. Just a thought... but maybe if it's a daily drive you're better with the upgrade.

If you try this go with the Polini spring, the Malossi ones are too stiff and get coil-bound as well, leading to drag. I've run the Polini on my DR130 for eons, it works well.

Cast iron Polini 130 in my PV, ET3 ignition, PM Pipe, 1800g flywheel. Revs to 9000, no problem so far with stock clutch.

which spring are you running socal? others have used the Malossi without trouble but my try was a disaster.

Standard spring. Clutch is from an ET3.

nice. kent_kurt if you go XL2 you will probably need to do something on the cover side as well or the throw won't work out so well. ask me how I know . I tried with standard primavera cover but couldn't get enough throw.

Hi John,
I suspect I'll need the custom SIP cover or have the existing one milled to fit the XL2.
https://www.sip-scootershop.com/en/products/clutch+cover+sip+for+vespa+_28615000

Exactly

Hi,
How did the scoot react to the lightened flywheel? Does it still idle well? Not sure if I should lighten the current (3000g) stock flywheel.

Thanks!
The constant operation of the clutch here in San Francisco (stop sign at every intersection...) kills my wrist (!), so I thought the XL2 would yield not only a stronger clutch, but a lighter pull.

I never ran a stock fly wheel so can't say how it compares. It definitely runs best with the idle set a little higher than my large frames.

1800 grams is a good weight for a road tune, 3000 grams is HEAVY.
Haven't tried XL2 clutch but of the clutches I've tried I will be sticking with the Crimaz CM4. Does need a spacer for the cover and I used only the lighter spring included in the last one I got. For some reason they put 2 springs in that one. Crimaz said both springs for M200 kit.
IIRC I was able to get the ET3 flywheel down to 2200 grams by removing material from the backside near the outer diameter without getting to close to the magnets.

The SIP 1,800g flywheel seems like a good option, and would allow me to go back to the stock flywheel in the future.
https://www.sip-scootershop.com/en/products/flywheel+sip+touren+for+vespa+_51004000
Seems to be out of stock at the moment.

Has anyone here tried one of these?