Description
The ProX Piston Kit for Yamaha SHO and FZR/FZS 8.6:1 applications is designed for modern high output 1.8L four stroke engines that combine supercharging with demanding personal watercraft use. This piston maintains an approximate 8.6:1 compression ratio, balancing detonation resistance with strong low and mid range torque. It is aimed at riders who want OEM style reliability with fresh internal components for hard recreational or performance use.
- Piston kit configured for Yamaha SHO (2008?2011) and FZR/FZS (2009?2012) 1.8L supercharged four stroke engines using 8.6:1 style compression.
- Includes piston, ring set, wrist pin, and circlips to renew one cylinder?s primary moving components.
- Manufactured from a low expansion, low friction alloy to maintain tight clearances under boost and high temperatures.
- CNC machined crown and skirt geometry support efficient combustion and smooth operation with factory ECU calibrations.
- Suitable for stock and mildly modified craft used for aggressive recreational riding or club level racing.
Installed in a properly inspected and honed cylinder, this ProX kit can restore strong cranking compression, clean idle, and powerful acceleration out of the hole. The ring package is tuned to handle the elevated cylinder pressures of supercharged use while maintaining good oil control. Riders can expect consistent performance across long sessions, provided fuel quality and cooling are maintained.
Engine builders should verify cylinder dimensions, check ring end gaps carefully, and confirm piston to wall clearances against ProX recommendations. Inspect rods, bearings, and the supercharger assembly, replace gaskets and seals, and ensure cooling and lubrication systems are fully functional. With careful assembly and a sensible break in period, the ProX SHO/FZR/FZS piston kit can support many more seasons of reliable high output Yamaha operation.
