Athena presents the new standard bore cylinder kit developed for Yamaha YZ 85 2019/2021.
This kit stands out from the OE one for some technical improvements, result of Athena’s experience and know-how. These refinements ensure extreme reliability and an optimal run.
All the components of the kit have been developed to resist at the highest temperatures, pressures and stresses and are perfectly replaceable to the OE ones. The cylinder kit was also tested on the track and on the dynamic and static bench to verify performance and quality.
This cylinder kit can be installed without any crankcase machining.
Compared to the original cylinder head, which includes 4 studs, Athena has studied and developed a head with 6 equally-spaced hub studs to distribute more evenly the clamping load. This improvement avoids leakage which could compromise engine performance.
The special stud on the exhaust allows for maximum cooling, optimal thermal dispersion and perfect engine efficiency.
The OE cylinder head, entirely in aluminum, was revised and engineered by Athena R&D technicians by providing an interchangeable dome, in order to ensure maximum flexibility in customization and better performance.
The cylinder head, redesigned for the 6 studs, is made of aluminum, while the central dome is manufactured from bronze, which ensures better thermal stability even at high temperatures.