Description
The ProX Piston Kit for Yamaha SHO and FZR/FZS 8.6:1 B size is tailored to cylinders that fall in the middle of the OEM bore tolerance band on 1.8L supercharged engines. Correct size matching is essential in these high specific?output platforms to manage noise, oil control, and ring stability. This kit keeps the stock compression character while refreshing worn components for demanding four stroke PWC duty.
- B size piston kit for Yamaha SHO (2008?2011) and FZR/FZS (2009?2012) 1.8L engines using approximately 8.6:1 compression.
- Includes B size piston, ring set, wrist pin, and circlips to rebuild one cylinder.
- Low expansion, low friction alloy and CNC machining provide OEM level fit in correctly gauged B?class cylinders.
- Crown and skirt profiles are optimized for efficient combustion and stable operation with factory or lightly tuned ECUs.
- Ideal for performance?minded owners who want reliable power for lake riding, offshore runs, or recreational racing.
When installed in a properly prepared B?grade cylinder, this ProX kit can restore compression, sharpen throttle response, and reduce oil consumption. The ring package is configured to cope with elevated boost pressures and high piston speeds while maintaining sealing over many operating hours. The engine feels stronger and more consistent across wide temperature and load ranges.
Builders should accurately measure cylinders to confirm B classification, set ring end gaps to recommended figures, and verify piston to wall clearance. Inspect the supercharger, intercooler, bearings, and gaskets, and ensure that fuel, cooling, and lubrication systems are in good order. With correct assembly techniques and break in, the ProX B size SHO/FZR/FZS piston kit can deliver long?term, high output reliability on the water.
