Athena introduces Big Bore Cylinder Kit for Yamaha YZ450F
Italian motorcycle parts and accessories specialist Athena has introduced a new big bore cylinder kit for the Yamaha YZ450F. Designed for riders looking to take their dirt bike to the next level, the kit is a bolt-on application that claims to improve engine efficiency, performance and response. Compatible with all Yamaha YZ450F models from 2020 to 2022, Athena bore kits are designed and manufactured in Italy.
According Athena, the Big Bore Kit can be installed without making any crankcase modifications. The kit consists of a lightweight forged piston, an aluminum cylinder head with a self-lubricating, anti-seize coating on the inside, and all gaskets and hardware needed for installation. Power gains are pegged to a six-horsepower increase, thanks to the bigger bore that’s been stretched to 102 millimeters. Additionally, the forged piston and reinforced inner cylinder walls help reduce friction, increasing engine efficiency and life.
The company says the big-bore kit has undergone rigorous dyno and track testing and delivered significant performance improvements, though Athena won’t provide exact numbers other than the six-horsepower gain. It also states that the engine compression ratio is slightly increased as a result of the upgrade. Athena’s Big Bore cylinder kit is available for 740.99 euros, which works out to around 738 USD.
For those looking for a more modest upgrade to their bike, Athena also offers a standard bore upgrade that follows the same specs as the stock engine. In this kit, the engine is reinforced for improved efficiency and longevity with a forged aluminum piston that has a molybdenum disulfide coating that reduces friction, improving performance and efficiency. Athena’s standard bore kit for the Yamaha YZ450F sells for 547.99 euros, or about US$546.