I have had my px fitted with a Polini 208 had everything ports and matched, 60 ml crank, t5 fourth gear, 30ml carb. Sip exhausts. Dyno tuned and well set up. That was two years ago. Basically I cannot decide what to do next, either a vespatronic, or would the new alloy Polini kit be the way to go? At the moment I managed 18hp, keen to crack 21hp.
light flyweel like vespatronic is not the best choice for me.
what are you looking for? torque or rpm?
new polini kit it's a big step, it have lot of torque and more rpm then cast iron one.
you need also a good cilynderhead, maybe the new pinasco vhr for c.60.