Description
Italian tuning specialists Polini are introducing their outstanding P.R.E. racing kit (Polini Racing Engine), and this is the engine's heart: Polini Cylinder P.R.E. 100cc Piaggio. The cylinder was designed to be combined with other P.R.E. components - crankshaft, crankcase, intake etc.
The cylinder is based on Polini's 125cc GP cylinder, the well-known racing kit that was used successfully at several Moto GP World Championships. It differs quite a bit from Polini's equally famous "Big Evo" cylinders in so far as stud bolt layout is completely different, allowing for much bigger cooling channels (close-deck system) and a very large exhaust port with central bridge. The cylinder head is the same as the one used in the GP 125cc kits, with a 6-scew fixing system and special combustion chamber.
- 50mm stroke
- 100mm connecting rod
- 1-ring piston, 14mm piston pin
- 5 transfer ports
- bridged exhaust port (for 3-screw flange)
- monobloc cylinder head
Note: due to the different stud bolt placement, this P.R.E. 100cc cylinder cannot be mounted with original crankcases. You can only use it with Polini's P.R.E. crankcase.
Not street-legal, designed for racing!
How to Install a cylinder on a scooter, motorcycle or moped
The cylinder or cylinder kit is the heart of the engine on scooters, motorcycles and mopeds. It consists of a cylinder, a piston with piston ring(s), a cylinder head and gaskets needed for installation.
The service life of a cylinder depends on whether it has been fitted correctly.

Tuning Level: High End racing
We categorize our products into different performance levels Original, Sport, Racing and High End , so that our customers can choose the right parts for their setup. It is really important to combine parts that belong to the same tuning level, this is especially true for cylinders, crankshafts and exhausts.
High End Racing products are exclusively designed for racing and should only be handled by tuning pros with the appropriate technical know-how. High-end racing parts often require modifications or machining of certain elements to accommodate the often larger components (larger crank webs, larger intake, etc.). Whether you stick with 50cc or increase the displacement, high-end racing parts offer much higher performance than the original parts and are the most powerful tuning parts.
Note: To ensure the reliability of the engine, it is important that the parts are compatible and that you do regular maintenance on your two-wheeler.
Aluminium cylinders
Aluminium cylinders are more powerful than cast iron cylinders, but require more regular maintenance and must be combined with different components such as a reinforced crankshaft and a larger carburetor.
How to run in an aluminium cylinder?
Aluminium cylinders should be run in for about 200 kilometers , and you should use a fully synthetic engine oil.
Note: To ensure optimum performance and reliability, it is advisable to measure the squish clearance. Just have a look at our tutorial How to adjust squish clearance.