PISTON KIT XR400 TRX400 86.00, FORGED WOSSNER 8604D100
4.1 Trustpilot 99.9% positive on eBay
Free UK delivery 2–4 business days
Spread the cost with 
18+, T&Cs apply
Wossner forged piston kit with an 86mm 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 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: Bore 86mm (85.94mm actual), Displacement 397 cm³, Stroke 70.00mm, Clearance 0.06mm, Wossner Compression Ratio 11.00:1, OEM Compression Ratio 10.00:1, Dome Volume +3.20 cm³, Compression Height 26.20mm. Cross-reference OEM Part Numbers: Wossner Piston 8604D100, Lock CW20, Pin WP052, Ring Set 860XSY, Rod P4021.
- SKU
- 56-W4606+100.WO
- Brand
- Wossner
- Availability
- In Stock (1)
- General Product Group
- Engine
- General Product Type
- Pistons & Kits
- General Size
- 86mm
- Variant Id
- 255771
FULL DESCRIPTION
Wossner 86mm Forged Piston Kit for Honda XR400 and TRX400
Upgrade your motorcycle or ATV's performance with this high-quality Wossner forged piston kit. Engineered for superior strength, durability, and heat transfer, this piston is manufactured in Germany to exacting standards. The advanced elliptical design ensures uniform bearing surface distribution, even under extreme operating temperatures, minimizing localized pressure and preventing piston failure. Experience a noticeable increase in engine performance due to the enhanced compression ratio.
Key Features:
- Forged construction for exceptional strength and longevity
- Optimized heat transfer for efficient cooling
- Elliptical piston design for consistent bearing surface under load
- Increased compression ratio for improved power output
- Premium German engineering and manufacturing
Specifications:
- Bore Size: 86.00mm (85.94mm actual)
- Displacement: 397 cm³
- Stroke: 70.00mm
- Piston Clearance: 0.06mm
- Wossner Compression Ratio: 11.00:1
- OEM Compression Ratio: 10.00:1
- Dome Volume: +3.20 cm³
- Compression Height: 26.20mm
Included Components:
- Wossner Piston: 8604D100
- Lock: CW20
- Pin: WP052
- Ring Set: 860XSY
- Rod: P4021
QUESTIONS? JUST ASK
Talk to John or Phil. Real people, Monday to Friday, 10:00 to 17:00.
Call or email us with your make, model and year and we will check it for you before you order.
UK delivery is £4.99, or free on orders over £60. Orders ship within 3 working days, then delivery takes 2–4 business days. Delivery details
Yes. You have 14 days from delivery to return it, unused and in its original packaging. Contact us first and we will send you the return instructions. Returns policy
By card, PayPal, Apple Pay or Google Pay, or spread the cost with Klarna. Payment is taken securely by Stripe, and the options for your order are shown at checkout.
More answers in our FAQ.
Trade pricing available
Buying parts for your business? Apply for a 2BrosParts trade account.