Definitly go for the polini 46mm! Loads of torque and a decent top speed.

i depends if you use a milling machine, and are good at it 😀
and you need the 19.5 phbg kit for it, its not going to do anything with a 13 13 carburator.

the problem with te reedvalve is that the canals are simelar to a stock engine,
so it recuires a lot of millin and tuning to get right for a malossi or athena

this is stock porting in a reedvalve

this was during the tuning period, more than 2 mm of material has to go

this is the end result for a brevattato 46.5
good power at the lower rpm, and a top speed of around 80/85 km.h

so we think youre better of with a polini engine, this has already good ports and it runs sick with a 46 polini cilinder

No it is this type:

http://www.spi-parts.com/scooter-parts-performance/piaggio/piaggio-mopeds/ciao/engine-crankcase-ciao-d-19.html

The one you are linking is for a maximum of 13mm carb’s and is more like a stock case with ports and large inlet ;)!

what kind of transmission you got?

normally this engine runs over 75 km/h, if you going to use a stock exhaust its a waste of money i think
better spends some euros on a variomatic, (1/13 gearing) with a 70cc DRevo and a good city power.
that wil do some wheelies like you never seen before 😀

the polini evo engine is a fast one, to make it run not faster than 55km/h wil be difficult 😀

if the power goes up, the speed wil also go up, unless you wanne ride 50km.h with 9000 rpm 😀

The 46mm polinie has smaller ports.
I think you be far better of wiht the 46mm. It has plenty of torque at low rpm.

It is not specially build for 46 mm cilinders but take an exhaust like the leovice handmade. It is a long pipe and doesn,t allow to much rpm,s.

But what ever you do ritze has right. You’ll fly.

But for what you say you want:
For much less money;

Take: a normal tuned blok, a dr evo 43mm,a 13/13caburator, a standaard vario and a leovice handmade.
Topspeed 65km/h and exelent pull up.

Cilinder: http://www.jmpbonderdelen.nl/vespa-ciao-si/motordelen/cilinders-vespa-ciao/dr-cilinder-43mm-vespa-p10.html This is piston pen 10mm, make sure that this is your size!

Caburateur http://www.jmpbonderdelen.nl/vespa-ciao-si/motordelen/carburateurs-vespa-ciao/carb-dellorto-ciao-13mm.html

I dont know for shure wat type exhaust fits on a bravo with a main stand.
The HM is scarce,they are not sold new any more.I think this will do:
http://www.jmpbonderdelen.nl/vespa-ciao-si/motordelen/vespa-ciao-uitlaten/proma-circuit-citta-ciao.html
Or for a standaard look; take a citty power. I do not know which one wil fit a bravo.

I see you already have a vario

If i were you I would go for:

Polini Speedengine
Polini 46mm
Original crankshaft
13/13 carburator
leovinci SP(silence power) exhaust (if you can find it, in Holland you wouldn’t find it new)