Vertex 24212C Cast Replica Piston Kit for KTM SX85 / Husqvarna TC85

The Vertex 24212C is a Cast Replica OEM-replacement piston kit designed for 85cc two-stroke motocross engines. Manufactured in Italy, Vertex is the OEM piston supplier to KTM and numerous European motorcycle and powersports manufacturers, making this kit a trusted choice for riders who demand factory-level fit and performance.

This kit features a 47mm cylinder bore diameter and a 46.96mm piston diameter, delivering a precise fit that minimizes blow-by, maximizes compression, and restores lost power. The piston is gravity-cast from an aluminum alloy with 18% silicone content for an exceptionally light yet strong construction. All piston skirts receive a Molybdenum Disulfide (MoS₂) coating for faster break-in and extended piston life. Each piston undergoes a T-5 heat treatment hardening and tempering cycle for improved durability under race conditions.

Kit Includes:

• Cast replica piston (OEM compression ratio)
• Piston ring(s)
• Wrist pin
• Circlips

Key Features:

• OEM-spec cast replica piston — meets or exceeds factory specifications
• Gravity-cast aluminum alloy with 18% silicone content for strength and light weight
• Molybdenum Disulfide skirt coating for fast break-in and long service life
• T-5 heat treatment hardening and tempering for durability
• Available in A, B, and C sizing grades for a perfect bore match
• Manufactured in Italy by Vertex — OEM supplier to KTM

The Vertex 24212C is an ideal OEM replacement for stock bore 85cc two-stroke motors and is fully suitable for competitive racing applications.