Cometic Top End Gasket Kit for Yamaha 77 mm Engines (C3549-EST)

The Cometic C3549-EST top end gasket kit is designed for Yamaha 4-stroke engines requiring reliable sealing during top-end service or rebuilds. This comprehensive kit includes the correct base gasket, head gasket, cylinder O-rings, and additional top-end-specific O-rings or seals needed for removal and installation. The kit is engineered for today’s high-output naturally aspirated and boosted machines, helping support dependable performance in demanding applications.
The MLS head gasket uses a multi-layer steel construction with embossed outer layers and a Viton rubber coating. This design promotes an even torque load across the gasket sealing surface, reducing bore distortion and helping improve piston ring sealing for enhanced power potential. Heat is drawn away from the combustion ring and distributed evenly across the gasket surface to help eliminate hot spots and reduce the risk of gasket failure under high cylinder pressure.
Cometic’s EST, or Extreme Sealing Technology, construction includes embossed stainless steel head, base, and rocker gaskets covered with a proprietary rubber material. These materials are selected to meet the sealing demands of high-horsepower 4-stroke engines while supporting consistent installation and long-term durability. The Cometic C3549-EST gasket kit is made in the USA and provides a complete, application-focused solution for Yamaha top-end maintenance.

Features:

• Application: Top-end gasket kit designed for Yamaha 4-stroke engines with a 77 mm cylinder specification

• Kit Contents: Includes base gasket, head gasket, cylinder O-rings, and other top-end-specific O-rings or seals

• MLS Construction: Multi-layer steel head gasket promotes even torque distribution across the sealing surface

• Sealing Performance: Helps reduce bore distortion and improve piston ring sealing for increased power potential

• EST Technology: Embossed stainless steel head, base, and rocker gaskets feature Cometic’s proprietary rubber coating

• Heat Management: Distributes heat evenly across the gasket surface to help eliminate hot spots and gasket failure

• Engine Compatibility: Designed for high-output naturally aspirated and boosted 4-stroke applications

• Manufacturing: Made in the USA

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