Supertech Performance VS-Y5.5E Yamaha 5.5mm Viton Exhaust Valve Stem Seal

The Supertech Performance VS-Y5.5E is a 5.5mm exhaust valve stem seal engineered for Yamaha applications. Manufactured by Supertech Performance — a leading developer of high-performance valvetrain components — this seal is constructed from a Viton (fluoroelastomer) compound, which provides superior resistance to high exhaust-side temperatures and aggressive operating conditions compared to standard rubber seals.

Supertech's exhaust valve stem seals are purpose-built to control oil consumption, prevent valve guide wear, and maintain consistent sealing performance under sustained high-RPM use. The Viton material is specifically chosen for exhaust positions where heat exposure is greatest, ensuring long-term durability and a reliable seal throughout the valve's service life.

Key Features:

• 5.5mm valve stem diameter — matches OEM stem sizing for precise fit
• Viton (high-temperature) compound — engineered for exhaust-side heat resistance
• Designed for Yamaha engine applications
• Controls oil consumption and protects valve guides
• Meets or exceeds OEM sealing performance
• Manufactured by Supertech Performance — a trusted name in motorsport valvetrain components

Supertech recommends replacing valve stem seals any time the cylinder head is serviced or when upgrading to performance valves. The VS-Y5.5E is sold individually; order the quantity needed to complete your application.