The WOSSNER Piston Kit measures 76.96 mm and is designed for select Yamaha motorcycles. The kit includes the piston, rings, wrist pin and pin locks. Its lightweight design uses tight piston wall clearance to support quieter engine operation.
Enhanced piston pin oiling slots, radial boss machining and annular grooves support improved wrist pin lubrication. The skirt is coated to help reduce friction and support break-in performance, while ring land treatment is designed to improve ring seal and oil control. A double-bridged forging design is used where noted.
Distributor part number: 09106138. Manufacturer part number: 8957DA. Fitment includes the 2020, 2022 and 2024 Yamaha WR250F; 2020, 2023 and 2025 Yamaha YZ250FX; and the 2020, 2025, 2026 and 2026 70th Anniversary Edition Yamaha YZ250F, as specified by the manufacturer.
Features:
- Piston size: 76.96 mm
- Enhanced oiling: Piston pin oiling slots, radial boss machining and annular grooves support improved wrist pin lubrication
- Lightweight design: Tight piston wall clearance supports quieter engine operation
- Skirt coating: Helps reduce friction and supports break-in performance
- Ring land treatment: Designed to improve ring seal and oil control
- Forging design: Double-bridged forging where noted
- Kit contents: Includes piston, rings, wrist pin and pin locks
- Fitment: Select 2020, 2022 and 2024 Yamaha WR250F; 2020, 2023 and 2025 Yamaha YZ250FX; and 2020, 2025, 2026 and 2026 70th Anniversary Edition Yamaha YZ250F models
Fitment:
2019 Yamaha YZ250F
2020 Yamaha WR250F
2020 Yamaha YZ250F
2020 Yamaha YZ250FX
2021 Yamaha WR250F
2021 Yamaha YZ250F
2021 Yamaha YZ250F Monster Energy Yamaha Racing Edition
2021 Yamaha YZ250FX
2022 Yamaha WR250F
2022 Yamaha YZ250F
2022 Yamaha YZ250F Monster Energy Yamaha Racing Edition
2022 Yamaha YZ250FX
2023 Yamaha WR250F
2023 Yamaha YZ250F
2023 Yamaha YZ250F Monster Energy Yamaha Racing Edition
2023 Yamaha YZ250FX
2024 Yamaha WR250F
2024 Yamaha YZ 250 F Monster Energy
2024 Yamaha YZ250F
2024 Yamaha YZ250F 50th Anniversary Edition
2024 Yamaha YZ250FX
2025 Yamaha WR250F
2025 Yamaha YZ250F
2025 Yamaha YZ250F Monster Energy Yamaha Racing Edition
2025 Yamaha YZ250FX
2026 Yamaha WR250F
2026 Yamaha YZ250F
2026 Yamaha YZ250F 70th Anniversary Edition
2026 Yamaha YZ250FX