50 Special engine conversion

Hi all, 

I just bought 50 Special which had a 125cc cylinder and a Polini carburator kit installed (something like this one: http://www.sip-scootershop.com/EN/Products/J17700160/Carburetor+Kit+POLINI+SHBC.aspx).

Now I want to set it back to 50cc, but I'm having some trouble. I installed a new 50cc cylinder and cylinderhead, but the carburator seems to be a problem.

I read that the carburator (19.19) would be too big for a 50cc cylinder. Can I adjust anything about it to make it ok, or will i need a new one? I just want the Vespa to ride around 50, not much faster. I'd also like to set the original intake manifold and air bellow back but everything needs to be compatible.

Thanks in advance!

You'll have to change the crankshaft as well.. And probaly the flywheel

E

You'll have to change the crankshaft as well.. And probaly the flywheel

E