Piston Kit for 4 Stroke

Upgrade your top end with a premium forged piston kit built for demanding 4-stroke riding. The WOSSNER Premium Series piston kit is engineered to improve ring seal, reduce friction and deliver consistent performance under load. With advanced wrist pin lubrication features and a coated skirt, it helps your engine run smoother, break in faster and stay reliable for longer service intervals.

This kit is a great choice when you’re rebuilding a worn top end or refreshing an engine for peak performance—helping restore compression, improve oil control and reduce unwanted mechanical noise thanks to tight piston wall clearance.

Key features:

• ✅ Enhanced piston pin oiling slots, radial boss machining and annular grooves for improved wrist pin lubrication
• ✅ Skirt coating to reduce friction and improve break-in performance
• ✅ Ring land treatment for improved ring seal and oil control

Benefits:

• 🔹 More efficient sealing and stable performance across hard riding conditions
• 🔹 Reduced friction for smoother operation and better durability
• 🔹 Complete kit simplifies rebuild planning (matched components in one box)

Technical specifications:

• 📌 Engine type: 4-Stroke
• 📌 Bore size: 77.01 mm (+0.01 mm oversize)
• 📌 Compression ratio: 14.0:1
• 📌 Piston material: Forged aluminum alloy
• 📌 Design notes: Double bridge forging (where noted), 3D crown, two-ring design

What’s included:

• Piston: #8957DB
• Ring set: #RIK77.00D
• Wrist pin: #WP070-SP
• Retaining clips: #CW16

Why choose this product?

• ⭐ Premium forged construction from WOSSNER for strength and long-term reliability
• ⭐ Engineered details focused on lubrication, sealing and reduced friction
• ⭐ Ideal solution for a proper 4-stroke top-end rebuild with all key components included