Sierra 18-5278 Tune Up Kit for Delco EST V-6 Marine Engines

The Sierra 18-5278 Tune Up Kit is designed specifically for Delco EST (Electronic Spark Timing) V-6 marine ignition systems used in inboard and sterndrive applications. This essential maintenance kit includes a heavy-duty distributor cap and precision-matched rotor, both engineered for the demanding marine environment.

Key Features:

• Complete tune-up kit for Delco EST V-6 HEI module-in-cap distributors
• Includes high-quality distributor cap with brass contacts for maximum conductivity
• Precision-matched rotor for consistent spark delivery
• Designed for marine engines prior to 2002
• Corrosion-resistant construction for harsh marine conditions

Replaces OEM Part Numbers:

• Mercruiser: 850484T1, 850484T3
• Mallory: 9-29321
• GLM: 71820
• CDI: E66-0035
• Pro Marine: 64484K

Regular replacement of ignition components ensures reliable engine starting, smoother idle, improved fuel efficiency, and prevents unexpected breakdowns on the water. Most marine mechanics recommend replacing the distributor cap and rotor every 100 engine hours or annually as preventative maintenance.