Description
The kit includes:
- 70cc Aluminium Cylinder, for 85mm conrod, with 6 transfer ports and bridged exhaust port
- Single-Ring Piston
- High-Compression Monobloc Cylinder Head
- Gasket Kit for mounting and adjusting squish
- Stud Bolt Set
- small end bearing, d=13mm (13x17x17.7mm)
The design of the kit was revised, among of the redesigned features:
- the kit got a fresh look as the cylinder was cast using the same mould as the 94cc cylinder.
- the exhaust port exit is equipped with a triangular adapter plate held in place by 3 screws (your exhaust flange will be mounted on this plate)
- the high-compression cylinder head is cast from one piece (monobloc) and precision machined (with internal water passage and centering pins)
Quality of materials and workmanship of this cylinder kit are definitely top-of-the-line.
Note 1: the exhaust flange has a different angle than the original exhaust port face and can only be used with a Polini Big Evo exhaust (same series).
Note 2: the Polini 70cc Cylinder Kit Evolution Piaggio NRG / Runner can only be mounted with a 85mm connecting rod (and a 17mm small end bearing), and you'll have to mill the crankcase to make room for the cylinder base.
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.