thanks a lot for considering my work.
I am Italian but I live in Switzerland for the moment, (I am planing to moove). I work on Scooter engines in a center in Geneva and on moto engines for another shop.
The thing is that here labor for hour cost is so high in comparison to the rest of europe (even though tax 7,6%) that I am working only with local customers.
Just to give you an idea :
the owner of the scooter center where I tune the engines bought a PX200 christmas three from SIP since he relised he would have paid more if he would have bought it from the official switzerland Piaggio distributor! So you can immagine !
So this means that for the same work the price would not be competitive with the rest of europe.
But I will be happy to help you out on my limit of knowledge and experience if you have any questions, expecially in this period that I have a lot of spare time since last week I had knee surgery.
What I can say about the list that you have is:
If you want to modify the barrell porting you will get more power but this power will be at higher rev and will loose at low and for two - riding it is not really what you need. (compromise)
If the inlet port has been well modified to accept the malossi reed
the modification of crankshaft (lip) will give you a little more, again at highish rev, but considering the cost…
I think in your case (if the case porting job has been correctly done) the thing will be of making it works at its best.
You could with a less invasive job and for less money profit of the better performance of a Keihin or a Mikuni carb.
You can make this thing go fast, but forget longer gear ratio. You will have to make the engine scream, squishing the gears all the way… if it is this that you want…
We have not just consider max power or have a look at a dyno graph. If you get more power it doesn’t mean you will like the way your engine feels. You could hate it even if it goes faster.