PISTON KIT 99-08 TRX XR 85.00, FORGED WOSSNER 8702DA 400
Wossner forged piston kit with an 85mm bore. Manufactured in Germany, this high-performance piston enhances strength, heat transfer, and durability. The elliptical design ensures uniform bearing surface distribution, reducing localized pressure and preventing piston collapse. Features include forged construction for superior strength and durability, optimized heat transfer to cylinder walls, elliptical design for uniform bearing surface under heat expansion, and increased compression ratio for improved engine performance. Specifications include bore of 85mm (84.94mm actual), displacement of 397 cm³, stroke of 70.00mm, clearance of 0.06mm, Wossner compression ratio of 12.50:1, OEM compression ratio of 10.00:1, dome volume of +8.40 cm³, and compression height of 26.20mm. Cross-reference OEM part numbers include Wossner Piston: 8702DA, Lock: CW20, Pin: WP052, Ring Set: 850XSY, Rod: P4021.
- SKU
- 56-W4628.A.WO
- Brand
- Wossner
- Availability
- In Stock (1)
FULL DESCRIPTION
Wossner Forged Piston Kit 85mm Bore
Upgrade your ATV's performance with the Wossner Forged Piston Kit. This high-performance piston, manufactured in Germany, features an 85mm bore for enhanced engine power. Its forged construction offers superior strength, durability, and improved heat transfer to cylinder walls.
The innovative elliptical design ensures uniform bearing surface distribution, effectively reducing localized pressure and preventing piston collapse, even under extreme conditions. This kit is designed to increase the compression ratio, leading to a noticeable boost in engine performance.
Key Features:
- Forged construction for exceptional strength and longevity.
- Optimized heat transfer for efficient cooling.
- Elliptical piston design for balanced bearing surface distribution.
- Increased compression ratio for improved power output.
- Premium quality manufacturing from Germany.
Specifications:
- Bore: 85mm (Actual 84.94mm)
- Displacement: 397 cm³
- Stroke: 70.00mm
- Piston Clearance: 0.06mm
- Wossner Compression Ratio: 12.50:1
- OEM Compression Ratio: 10.00:1
- Dome Volume: +8.40 cm³
- Compression Height: 26.20mm


