Cast Piston Kit

The ProX Cast Piston Kit is designed as a stable, OEM-replica replacement for 2-stroke engines—ideal when you want dependable performance without guesswork. ProX piston designs typically follow the original stock configuration, and are refined when ProX engineers identify opportunities to improve performance and durability.

Manufactured using gravity casting from an aluminum alloy with approximately 18% silicon, this piston is built to control heat-related growth. Silicon plays a key role by reducing thermal expansion, helping the piston maintain correct running clearances and improving reliability under demanding riding conditions.

Key features:

• ✅ Cast replica stability: ProX cast pistons are known for very stable operation.
• ✅ High-silicon alloy: ~18% silicon content helps minimize thermal expansion.
• ✅ Ready-to-fit kit format: supplied as a piston kit with steel ring material and a moly-coated skirt.

Benefits of use:

• 🔹 OEM-style fit & function: designed to replicate stock performance characteristics for predictable results.
• 🔹 Improved heat management: reduced expansion helps protect the cylinder/piston interface and supports long service life.
• 🔹 Good choice for rebuilds: a reliable solution for routine top-end service on 2-stroke engines.

Technical specifications:

• 📌 Brand: PROX
• 📌 Vendor Part Number: 01.4322.D
• 📌 Engine type: 2-Stroke
• 📌 Piston diameter: 66.37 mm
• 📌 Piston size: Standard Size D
• 📌 Material: Aluminum Alloy, Cast
• 📌 Skirt coating: Moly Coated
• 📌 Ring material: Steel
• 📌 Style: Cast Replica
• 📌 Units: Kit

Why choose this product?
⭐ Proven ProX manufacturing focused on stability and OEM-level compatibility
⭐ High-silicon cast construction to help control thermal expansion
⭐ A practical, dependable piston kit for 2-stroke top-end maintenance