PK50 to PK125 conversion (partslist)

I’m doing a conversion from a standard PK 50 engine to
a PK 125 (except i’m using a Polini 130 kit) so i’m aware
that i need a new PK 125 transmission and a new PK 125 crankshaft, but i can’t seem to find the right ones…?

So i need a partslist for ordering this things, and if there is
something else missing to complete this conversion, please
let me know…

Thanks in advance…

Regards Alex

if its pk or pkxl  then this will depend on the thickness of flywheel stub on crankshaft you wish to use.


2.56 primary needed to polini130. pk or pkxl motor


reed manifold or standard rotary valve induction also determines your choice of crank.

Thanks, but do you also know what crankshaft i need…?