Athena Cylinder Kit Big Bore 47.6mm Bore P400485100089

Athena is pleased to announce an absolute novelty in the world of air cooled vertical Yamaha-Minarelli engines and therefore for legendary applications such as MBK Booster / Yamaha BW's or the iconic Aprilia SR*.

With this brand new big bore cylinder kit, Athena R&D department brings on this cylinder technical solutions usually applied only on high performance engines, such as on the 2T Racing GPs. The multiple innovative technical solutions introduced in this project allow to reach performances never achieved before with this engine.

With this new cylinder kit Athena is introducing many solutions never seen before on these applications. The result is just the best performing cylinder kit ever designed in its category.

A REVOLUTION ON THE PORTS

Athena's technicians wide experience in the 2T sector allowed them to approach this cylinder challenging the traditional design. The intake and exhaust ports have been totally redesigned: analyzing the thermo-fluid dynamics of the engine, overall performances have been highly improved in terms of power and torque, achieving new levels for the first time ever. The intake port is reinvented, adding a CNC machined fifth port to grant a higher gas flow incoming in the combustion chamber.

Using the innovative fixing system directly on the crankcase without using stud bolts, Athena developed an exhaust outlet with a bigger oval shape and side auxiliary ports. This solution has been applied for the first time ever on this kind of cylinders.

REINVENTED PATENTED FIXING SYSTEM

The regular head and cylinder tightening based on studs has been eliminated introducing a new system patented by Athena of special bolts pretty close to the ones used in the high-level performing engines. Tightening the cylinder to the crankcase (Racing type) with these bolts and a special Allen key leads to a reduction of the thermal expansion of the cylinder, bringing a more efficient tightening and on the other hand allows the sophisticated redesign of the exhaust port that makes this product so special and unique.

NEW RACING PISTON

The flat head piston has been developed focusing in particular on the interaction with the intake. The CNC machined opening on the piston skirt is designed to maximize the inlet flow, to allow greater pressure on the pump casing and better lubrication of the needle bearing.

• Redesigned intake and exhaust ports
• Redesigned piston to maximize inlet flow
• Reinvented and Patented Athena fixing system

Brand: Athena
Part Number: P400485100089

Fitment:

• Aprilia SR50 FINO 1994 MOT. VERT 1994
• Yamaha Big Wheel 50 BW50 BUMP 1997-1998
• Yamaha Big Wheel 50 BW50 NAKED 2003-2009
• Yamaha Big Wheel 50 BW50 NEXT GENERATION 1997-2003
• Yamaha Big Wheel 50 BW50 NEXT GENERATION KAT 1999-2000
• Yamaha Big Wheel 50 BW50 ORIGINAL 2003
• Yamaha Big Wheel 50 BW50 ORIGINAL / SPY 1997-2002
• Yamaha Big Wheel 50 BW50 R 2001
• Yamaha Big Wheel 50 BW50 2007-2016
• Yamaha Zuma 50 CW50 BW'S ORIGINAL 2002
• Yamaha Zuma 50 CW50 L BW'S 2003
• Yamaha Zuma 50 CW50 RS SPY 1995-1998
• Yamaha Zuma 50 CW50 SP BW'S ORIGINAL 2002

Note: Image is for reference only, actual product may vary slightly.