Sierra 18-8810-1 MagForce Marine Spark Plug Wire Set, 6-Cylinder, for Mercruiser Sterndrive and OMC Engines

The Sierra 18-8810-1 is a premium MagForce marine spark plug wire set built for 6-cylinder Mercruiser Sterndrive and OMC engines with EST Electronic ignition. Each wire uses a Kevlar core paired with a durable stainless steel wound conductor, delivering the electrical conductivity needed for consistent horsepower and reliable engine performance. The wires are finished with premium silicone jacketing and silicone boots that hold up under sustained high engine-bay temperatures, protecting the set from heat degradation over time. Silicone construction also provides superior RFI suppression, which matters for boats running sensitive onboard electronics, gauges, and marine electronics that can otherwise pick up ignition interference.

Terminal ends are stainless steel at both the spark plug and distributor connections, resisting the corrosion that saltwater and engine-bay moisture cause on lesser terminal materials, so the set maintains conductivity and a solid connection over its service life. The set is finished in white and is a direct fit for the 6-cylinder Mercruiser Sterndrive and OMC applications it is designed for. As with all Sierra parts, buyers should verify this is the correct wire set for their specific engine application before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8810-1
• Number of Cylinders: 6
• Ignition Type: EST Electronic
• Connector Type: Terminal Block
• Core Material: Kevlar
• Conductor Material: Stainless Steel Wound
• Jacket/Boot Material: Silicone
• Color: White
• Weight: 1.37 pounds
• UPC: 808282194390

Fitment

• 6-cylinder Mercruiser Sterndrive engines
• 6-cylinder OMC engines
• EST Electronic ignition systems

Replaces (OEM)

• 84-813720A11
• 84-816761Q16
• 503751

Frequently Asked Questions

What engines does the Sierra 18-8810-1 spark plug wire set fit? The 18-8810-1 is designed for 6-cylinder Mercruiser Sterndrive and OMC engines that use EST Electronic ignition.

How many cylinders does this wire set cover? This is a 6-cylinder set, matching the number of spark plug wires needed for a 6-cylinder Mercruiser Sterndrive or OMC engine.

What OEM part numbers does the 18-8810-1 replace? It replaces Mercruiser Stern Drive numbers 84-813720A11 and 84-816761Q16, as well as OMC number 503751.

Is this a genuine Sierra part or an aftermarket copy? The 18-8810-1 is a Sierra-manufactured MagForce wire set, sold as a direct replacement carrying Sierra's own part number and warranty coverage.

What is the wire core made of? Each wire in the Sierra 18-8810-1 set has a Kevlar core paired with a stainless steel wound conductor for durability and consistent electrical performance.

Will these wires hold up to engine heat? Yes, the 18-8810-1 uses premium silicone jacketing and silicone boots specifically for high-temperature protection in the engine bay.

Do these wires cause interference with onboard electronics? No, the silicone construction of the 18-8810-1 set provides superior RFI suppression, which helps prevent ignition interference with sensitive electronic systems on board.

What color is the Sierra 18-8810-1 wire set? This spark plug wire set is finished in white.

How much does the 18-8810-1 weigh? The Sierra 18-8810-1 spark plug wire set weighs 1.37 pounds.

Are the terminal ends resistant to corrosion? Yes, the spark plug and distributor terminal ends on the 18-8810-1 are stainless steel, which resists corrosion for maximum conductivity over time.

What is included with the 18-8810-1? The 18-8810-1 includes the complete set of spark plug wires with terminal ends for a 6-cylinder Mercruiser Sterndrive or OMC engine application.

How do I confirm the 18-8810-1 is correct for my boat? Because ignition wire sets are application-specific, verify the 18-8810-1 matches your engine's cylinder count and EST Electronic ignition setup before ordering.