I bought a Pinasco 225 Supersport kit and a 60mm crank by the same manufacturer to fit on my P2 when the kit came out 4 years ago. The idea was to run a slighly more powerful but still reliable cylinder on my daily bike. Although the "adapting" was a bitch (cylinder exhaust stud too thick for any of my exhaust pipes, seals blowing because compression too high, spark plugs loose because thread in head a bit off, slots in crank too narrow for most woodruff keys, etc.), once sorted out, it was a nice and torquey kit with the benefit of keeping an SI type carb, rotary induction, and autolube.
But at little under 2500 miles, with no warning signs, the bottom half of the piston broke (under the pin).
I should mention that the kit was in no way abused during its short life: just zipping around town and half-hour freeway runs mostly.
I would have cast this off as an annoying but freak incident, had it not been that a friend in the neighborhood broke the same piston in the same manner twice in the same period:
I've been running Polini and Malossi kits on both T5s and P2s for years, with the occasional predictable heat seize, but never have I experienced a newish piston breaking under no stress at all. Most Pinasco veterans had told me these kits (well, the previous ones actually) were made to be thrashed all day.
So I was wondering: has anyone else experienced this kind of trouble with pistons from the 225 kit breaking in this unexpected way? Just wondering if there's a pattern....
Last edited by Frank N. Stein on Sat Dec 15, 2018 4:56 pm; edited 1 time in total