Athena racing 70cc cylinder kit for Minarelli 50cc 2-stroke horizontal engines.

This cylinder kit is a revolution in scooter tuning. The cylinder has features normally reserved for MX and GP racing engines. The main feature of this cylinder is the patent pending flange mount system, this system removes the restrictions of traditional cylinder studs. Thermo-fluid dynamic analysis has shown a large oval exhaust port with large auxiliary ports allows Athena to increase the possible power and torque provided by a 70cc cylinder, with a expected power output of 17-19HP with the right setup.

The cylinder head protrudes into the cylinder by 1.5mm and is mounted with short bolts, providing a self centred and very stable combustion chamber. The flat top piston has also been modified for this cylinder kit, the CNC-machined window provides maximum flow, ensuring complete crankcase filling and improved lubrication of the small end bearing.

The flange mount system removes the traditional long cylinder studs in favour of bolts mounting the cylinder at its base, Allen screws and a special Allen key is included.

Athena have also produced a racing exhaust system that perfectly matches the performance of this cylinder kit, is recommended to pair the Athena exhaust with this cylinder kit.

A  high quality 12mm racing crankshaft is required to fit this cylinder.

A 24/26mm PWK type carb with large intake system is recommended by Athena

Capacity: 69.8cc
Bore: 47.6mm
Stroke: 47.6mm
Compression ratio: 13.8:1
Gudgeon in: 12mm (oversized)

Included: cylinder, head, piston kit, gasket set, small end bearing, 2x gaskets & fitting kit.

Athena P400485100099