20+ Yamaha YZ450F YZ 450F 102mm 496cc Athena Big Bore Cylinder Kit Piston Gasket

A powerful engine with added performance: Athena is pleased to present the new big bore cylinder kit, developed for Yamaha YZ 450 F 2020-2022.

• The Yamaha YZ 450 F 2020-2022 engine is identical in regard to it’s compactness and lightweight feel. Along with the new Athena Big Bore cylinder kit, it boasts of excellent torque and power performance, delivering over six hp more than the original cylinder kit.

• Besides modifying the cylinder following Yamaha’s overhaul of the YZ 450 F engines after 2020, which changed the shape and inclination of the cylinder along with the oil passages, Athena engineers adjusted the machining to deliver a significant increase in the bore to Ø102 mm.
• Despite the increased size, the R&D department has designed this kit without having to bore the crankcases and with no additional machining required.
• Produced by gravity casting and a heat treat process, designed to improve its mechanical characteristics, the Athena cylinder ensures maximum resistance even at the highest temperatures. The liner is designed to ensure a premium smooth finish lasting a lifetime, due to a special coating in nickel and silicon carbides.

• Designed by Athena engineers, who studied the cylinder and created a system that outperforms the original. The piston delivers a superior power explosion at low to medium revs and at high engine speeds. The results, which also showed a marked increase in torque and compression ratio, came from bench and track tests.
• Manufactured by reverse extrusion, using high-precision technology, this forged piston delivers ideal flow and features polished profiles for perfect front flame amplification.
• The segments provide an optimized tangential load for a correct balance between lubrication and sealing, while the piston pin comes in high-quality alloy steel for maximum resistance.

• The kit contains the gaskets required to install the cylinder kit, including the cylinder head gasket and base gasket, redesigned by Athena engineers to fit the new Yamaha cylinder oil passages.
• The rubber-coated metal base gasket features silicon creasing in critical areas on its surface that R&D engineers identified during the design phase. The creasing is near the crankcase joints and is ideal for preventing liquid leakage.
• In contrast, the MLS (Multi-Layer Steel gasket) head gasket is constructed with three blades: the outer blades are in rubberized sheet metal, while the central one is in AISI301 stainless steel to withstand high levels of compression.