Cometic C9890-045 EST Motor Only Gasket Kit Harley Evolution Big Twin .045" MLS

The Cometic C9890-045 is an Extreme Sealing Technology (EST) Motor Only Gasket Kit engineered for Harley-Davidson Evolution Big Twin engines (1992–1999).

The standout component is the .045" Multi-Layer Steel (MLS) cylinder head gasket, constructed from two embossed Viton-coated stainless steel outer layers surrounding a variable stainless steel center layer. This MLS design accommodates any combination of head and cylinder materials, provides consistent load distribution, and eliminates the need for re-torque after initial torque set.

Kit Highlights:

• MLS Head Gaskets (.045" thickness) — Viton-coated stainless steel layers for superior sealing across varied surface finishes
• Viton Rubber-Coated Steel Base Gaskets — Single-layer steel core with Viton rubber coating for a reliable, leak-free base seal
• AFM Engine Cover Gaskets — Aluminum Foam Material made from chemically blown nitrile synthetic rubber bonded to an aluminum core; installs dry, no re-torque required
• AFM Temperature Resistance — Rated for over 250°F with 85% recovery and strong torque retention
• Race-Style Exhaust Gaskets — Designed to prevent fraying into the port
• Copper Washers & Viton O-Rings — Used to seal drain plugs and engine covers with stock o-ring seals

Cometic's EST gasket kits meet and exceed OEM specifications, making the C9890-045 an ideal choice for engine rebuilds, top-end refreshes, or performance builds on the Evolution Big Twin platform.