Cylinder Kit ATHENA P400485100108 Big Bore d102 mm, 497 cc to increase performance

Take your Yamaha YZ 450 F performance to the next level with the Athena Big Bore Cylinder Kit, engineered to increase engine displacement while maintaining excellent mechanical reliability.

Specifically developed for the Yamaha YZ 450 F, this Big Bore Kit features a carefully optimized combination of lightweight reciprocating components, high-strength materials, and revised engine parameters designed to deliver increased performance without compromising rideability.

More Displacement, More Performance

The increased displacement unlocks greater engine performance, delivering stronger power delivery and increased engine response.

Athena did not simply increase cylinder capacity. The entire top-end assembly was engineered as a system to achieve the optimal balance between performance, durability, and rideability.

Lightweight Piston for Maximum Performance

The piston was specifically engineered to minimize weight while maintaining the strength required for high-performance engine operation.

Reducing reciprocating mass helps limit the forces and loads transmitted to the connecting rod, contributing to engine durability while allowing the increased displacement to deliver its full performance potential.

The result is a piston designed to combine low weight, high strength, and maximum performance.

Made-in-Italy DLC-Coated Wrist Pin

The kit features a Made-in-Italy wrist pin with DLC (Diamond-Like Carbon) coating, developed to withstand the increased loads generated by the Big Bore configuration.

The DLC coating provides excellent surface hardness and wear resistance, helping ensure reliable operation under the high mechanical stresses of a high-performance motocross engine.

Optimized Compression Ratio

The increased displacement is combined with a revised compression ratio, engineered to deliver an effective and controllable power character.

The goal is to provide a more balanced engine response and improved rideability across a wide range of riding conditions, from motocross tracks to more technical terrain.

Reinforced Cylinder for Increased Mechanical Strength

Increasing engine displacement also increases the mechanical loads acting on the top end. The Athena cylinder has therefore been specifically reinforced to maintain high mechanical strength under demanding operating conditions.

The design combines increased performance with structural durability, allowing riders to fully exploit the potential of the Big Bore configuration.

Engineered Specifically for the Yamaha YZ 450 F

The Athena Big Bore Cylinder Kit was specifically developed for the Yamaha YZ 450 F, with dedicated engineering solutions designed around the original engine architecture.

It is the ideal solution for riders and engine builders looking to increase the performance potential of the Yamaha engine while maintaining control, reliability, and premium build quality.

Athena Performance Engineering

Athena's experience in developing high-performance components for motorsport is reflected in a Big Bore Kit engineered to deliver a meaningful and usable performance increase.

More displacement, optimized reciprocating mass, and components engineered for increased loads: a combination designed to unlock the full potential of the Yamaha YZ 450 F.

Race Use Only Product – Not intended for street use.

WARNING: the cylinder head and base gaskets contained in the kit are specifically developed for Athena cylinders kits. Whenever the cylinder kit is disassembled, replace the gaskets with the specific Athena spare gasket kit: DO NOT use OE replacement gaskets.

PDF Mounting sheet - montážní list