Description
Polini Piston "Big Evo" 70cc d=47.6mm piston pin=12mm (B) Yamaha Aerox / Piaggio NRG, spare piston for Polini Evolution 70cc cylinder for Minarelli and Piaggio. We carry a huge selection of tuning and spare parts by Polini, well-known scooter and moped expert from Bergamo in Northern Italy.
- for Polini Evolution 70cc
- size B piston / 47.555mm / 12mm pin
- fits Minarelli + Piaggio engines
When to replace the piston?
To find out when the piston on your motorcycle, scooter or moped needs to be replaced, it's best to check your bike's manual. You can also keep an eye out for certain symptoms such as loss of compression, loss of power or oil consumption (only for a four-stroke piston).
Extending Piston life
To extend the life of the piston and reduce cylinder wear, it is recommended that you replace the piston rings on an alternating basis. This method maximizes piston life and improves engine performance.
It is important that you replace cylinder gaskets and piston circlips each time you disassemble the cylinder and piston. Failure to do so can result in oil leaks and engine damage.
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.