Sierra 18-8834-1 Spark Plug Wire Set for MerCruiser 350 Mag MPI HEI Stern Drives

The Sierra 18-8834-1 is a premium replacement spark plug wire set engineered specifically for MerCruiser 350 Mag MPI MIE Gen+ stern drive engines equipped with the Mercury HEI ignition system. Designed to meet or exceed OEM specifications, this set is a direct replacement for Mercury Marine OEM part number 84-816608Q83.

Sierra's MagForce ignition wires are built exclusively for the harsh marine environment, delivering maximum voltage to each cylinder while protecting sensitive onboard electronics from RFI and EMI interference. The set includes 8 spark plug wires in application-specific lengths plus a coil wire for a perfect, custom fit.

What's Included:

• (1) Spark plug wire — 29"
• (2) Spark plug wires — 33"
• (3) Spark plug wires — 39"
• (2) Spark plug wires — 45"
• (1) Coil wire — 12"

Key Features:

• Kevlar® aramid inner core for maximum tensile strength, conductor integrity, and long service life
• Durable stainless steel wound conductor for maximum horsepower and engine performance
• High-tear-strength silicone jacket rated to 500°F with reinforcing mesh for ultimate heat protection
• Custom magnetic suppression core engineered for your specific application
• Pure silicone OE-style boots lock out heat, dirt, and moisture
• Stainless steel snap-lock terminals at spark plug and distributor ends resist corrosion and prevent terminal pull-off
• Electronics friendly — superior RFI/EMI suppression protects GPS, VHF, Loran, and electronic engine controls
• Compatible with original equipment and aftermarket ignition systems
• Tested to ISO quality standards
• Backed by Sierra's industry-leading customer satisfaction warranty

OEM Cross-Reference: Replaces Mercury Marine 84-816608Q83 / 84-816608A83.

Sierra has been a trusted name in marine engine parts for over 50 years, offering high-quality replacements engineered to withstand the demands of the marine environment. This spark plug wire set restores reliable ignition performance, improves engine efficiency, and helps maximize fuel economy on your MerCruiser stern drive.