Description
Metrakit Pro Race 4 80cc Minarelli AM6 cylinder kit
High-quality racing and tuning parts from Metrakit: Metrakit 77cc cylinder kit with 50mm bore, the Pro Race aluminum cylinder in its 4th incarnation. Metrakit has once again improved their already fantastic Pro Race kit, this time increasing the bore and piston from 47.6 mm to 50 mm and increasing the displacement from 70cc to a whopping 77cc.
The new Pro Race version for comes with a CNC-machined golden cylinder head, for a modern look and efficient cooling.
Performance Metrakit Pro Race 77cc
The 77cc Pro Race 4 is one of the most powerful racing cylinders on the market. More power, improved torque, better acceleration and, above all, the cylinder can live up to its full potential in the higher rev range. Nevertheless, the cylinder has a very nice power curve due to the 3-port exhaust design when combined with a suitable 80cc exhaust system.
We also recommend the installation of a high-end crankshaft, a 28mm carburetor and a reinforced clutch for this cylinder.
WITHOUT road approval / homologation.
Scope of delivery Metrakit Pro Race AM6
- 77cc aluminum cylinder with 5 transfer ports, exhaust with boost ports
- Coated 50mm piston from Athena, 1 chrome-plated ring 0.8mm
- Cylinder head 2-piece / modular, gold
- Water connection
- Gasket set with 4 base gaskets (squish)
Metrakit Pro Race
The Pro Race series from Metrakit consists of extremely powerful high-end parts for 50cc scooters and motorcycles, e.g. cylinders, crankshafts and exhaust systems.
The motto of this series is pretty straightforward: maximum performance. The Pro Race products offer very high maximum power with an emphasis on the upper RPM range, making them ideal for use on the race track.
To make full use of the power, we recommend using a carburetor with a large diameter, a large-volume intake system and a reinforced clutch.
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.
| Cylinder Kit Metrakit 77cc Pro Race 4 AM6 Machined Head | |
|---|---|
| Article no. | MK805R0360 |
| EAN | 9505888685536 |
| Weight | 1,80 kg |
| Series | Pro Race |
| Brand | Metrakit |
| Product type | Cylinder kit |
| Tuning level | High-end |
| Displacement | 77cc |
| Piston pin | 12 mm |
| Cylinder material | Aluminium |
| Bore | 50 mm |
| Stroke | Original |
| Conrod length | Standard |
| Spark plug thread | M14 long |