This cast iron kit is set up for more power in the higher RPMs, at the expense of a little bottom-end and midrange power. Extremely high quality is known for! A recommended carburation upgrade is the reed valve kit . We also recommend the Polini or Leo Vinci exhaust. Check our our entire line of Performance Carburetors . This kit will fit on all vera and ET3 scooters, and also post-1965 Vespa 90. Additionally, it will fit on some Vespa 50’s, but we recommend upgrading your gearing on 50cc engines at the same time. You will need four long cylinder studs and a vera shroud to use on these models. This will not fit on ’63-64 model Vespa 90 (small door models). Sorry; no cylinder kit will! ***PLEASE NOTE*** Performance upgrades are considered racing parts and are not covered by warranty. There are too many variables involved with user-installed parts, and pushing the limits of your engine tends to wear parts faster. Use at your own risk! Replacement pistons can be ordered here: standard 1st oversize 2nd oversize Replacement rings can be ordered here. Looking for more performance upgrades We also carry a vera high performance kit that inlcludes this cylinder!