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The new 70cc Athena cylinder kit for Yamaha-Minarelli Vertical Engines (CW)

18 November 2021

Alonte (VI), Italy, 11 November 2021. Athena, a leading company in the high-performance motorbike parts market, launches the new big bore cylinder kit for Yamaha-Minarelli vertical air-cooled engines, which equips iconic scooters such as MBK Booster, Yamaha BW's, or the legendary Aprilia SR. This special cylinder kit features innovative technical solutions with patent pending, enabling unprecedented performance and power that can reach as high as 19 HP.

The exclusive technical features of this cylinder kit are:


Entirely reinvented fastening system.
The normal cylinder head and cylinder clamping, based on studs, has been eliminated to introduce a new system with special bolts, adopted in racing applications. This solution reduces cylinder expansion, thereby ensuring more efficient clamping, and allows for a sophisticated redesign of the exhaust port.


Redesigned intake and exhaust ports.
The intake features a CNC-machined fifth port that ensures a greater flow of fresh intake gases, while the oversized exhaust port has an oval geometry with side boosters. This last solution cannot be found on any other cylinder of this type on the market today. The result is the highest performance cylinder kit of its
kind ever conceived.


Special, flat-head piston.
Development of the piston was conducted focusing on the interaction with the intake. The CNC-machined window on the casing is designed to maximise the intake flow, thereby favouring greater pressure on the pump casing and better lubrication of the roller cage.

Athena's range for scooters equipped with this engine includes many other related products, such as racing crankshafts, 28mm carburetor with dedicated air filter, and the Big Valve System, an intake system with reed valve that further increases and optimises intake gas flow and, therefore, engine operation.

The new Athena big bore cylinder kit for Minarelli 2-stroke vertical engines is available at a suggested retail price of €299.