It’s been a while since I rode the scooter, I took it out last weekend and had a blast around the Sydney Hills, got to thinking about the port timing (as you do). I fittted a long stroke maz crank in it about 3 years ago and a Polini 208, worb5 centre plug head to accommodate the extra 1.5mm. Squish is about 1.1 mm from memory. Quite a few other things but that’s the main stuff.
Now ever since I spoke to Terry (RIP) at Taffspeed I’ve been thinking about the wisdom of the long stroke crank. He told me I that by installing the crank I was messing with Mr. Polini’s porting, which makes sense to me the more I think about it. I wonder if there are any guru’s out there who have managed to work it out properly. All I hear is that the 60mm cranks make more power, or move the available power lower down the rev range, but I have never seen any difference to be honest, short of putting a standard crank back in mine I won’t really know but I thought I would ask out of curiosity.
Can anyone convince me that they do create more power without having to report the cylinder?