Brian Crower BC3995 Valve Stem Seals for Yamaha YXZ 998

The Brian Crower BC3995 are high-performance Viton valve stem seals engineered for the Yamaha YXZ 998 engine. Compatible with both stock and aftermarket valve guides (including BC3967), these seals are a direct upgrade for builders looking for reliable oil control in performance applications.

Valve stem seals play a critical role in engine longevity—they allow a carefully controlled amount of oil from the cylinder head into the combustion chamber to lubricate the rotating valve stem within the guide. The BC3995 seals use premium Viton material, a high-temperature, chemically resistant compound that outperforms standard rubber seals under sustained high-load and high-rpm conditions.

Key Features:

• Viton construction for superior heat and chemical resistance
• Precision-engineered to fit stock OEM valve guides as well as aftermarket guides (BC3967)
• Covers both intake and exhaust valve positions
• Produced from high-performance materials for increased part life and reduced wear
• Designed for high-boost and high-rpm performance builds

Whether rebuilding the stock top end or upgrading with Brian Crower valvetrain components, the BC3995 valve stem seals deliver consistent oil control and long-lasting performance in the Yamaha YXZ 998 engine platform.