Sierra 18-8840-1 Spark Plug Wire Set for 150 & 175 HP Outboard Engines

The Sierra 18-8840-1 is an inductive spark plug wire set engineered for 150 and 175 hp outboard engines. The set includes two 14 inch wires and two 16 inch wires, giving each cylinder the correct reach without excess slack or strain on the terminals. Each wire uses a Kevlar core wound with a stainless steel conductor, paired with a Mag/Wire wound core design that suppresses radio frequency interference (RFI) and electromagnetic interference (EMI) so onboard electronics run cleanly alongside the ignition system.

The wires are finished with premium silicone jacketing and boots for protection against the high heat found near the powerhead, and the terminal ends use corrosion resistant stainless steel spark plug and distributor terminals for consistent conductivity in the marine environment. Moisture-proof, molded distributor insulators seal out water intrusion at the distributor connection, while a high tensile strength membrane and nylon reinforcing tape add durability against vibration, chafing, and heat over the life of the set. This wire set is built to meet or exceed the performance of the original equipment wiring it replaces.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8840-1
• Engine Fitment: 150 & 175 hp Outboard
• Wire Lengths: Two 14 inch, Two 16 inch
• Material: Silicone, Stainless Steel, Kevlar
• Core Type: Mag/Wire wound core
• Terminal Material: Stainless steel spark plug and distributor terminals
• Insulator: Moisture-proof, molded distributor insulators
• Item Dimensions: 10.25 x 7.25 x 2.75 inches
• Weight: 0.93 pounds
• Number of Items: 1
• UPC: 808282194659

Fitment

• 150 & 175 hp Outboard engines

Frequently Asked Questions

What engines does the Sierra 18-8840-1 wire set fit? The Sierra 18-8840-1 is built for 150 and 175 hp outboard engines.

How many wires come in the 18-8840-1 set and what lengths are they? The set includes two 14 inch wires and two 16 inch wires, sized for the 150 & 175 hp outboard engine layout.

What is the wire core made of? Each wire in the Sierra 18-8840-1 set uses a Kevlar core wound with a stainless steel conductor for durability and consistent conductivity.

Does this wire set help with radio or electronic interference? Yes. The Mag/Wire wound core in the 18-8840-1 provides suppression of radio frequency interference (RFI) and electromagnetic interference (EMI).

Is this a direct OEM replacement or an aftermarket part? Sierra 18-8840-1 is an aftermarket wire set engineered to meet or exceed the performance of the original equipment wiring it replaces.

How much does the 18-8840-1 spark plug wire set weigh? The Sierra 18-8840-1 wire set weighs 0.93 pounds.

What are the boots and jacketing made of? The wires use premium silicone jacketing and boots, chosen for high temperature protection near the outboard powerhead.

Are the terminals resistant to corrosion? Yes, the 18-8840-1 uses corrosion resistant stainless steel spark plug and distributor terminals designed for the marine environment.

What protects the distributor connection from moisture? Moisture-proof, molded distributor insulators seal the distributor connection on the Sierra 18-8840-1 set.

What is included in the box? The Sierra 18-8840-1 package contains one complete spark plug wire set: two 14 inch wires and two 16 inch wires.

How is the 18-8840-1 different from Sierra's other outboard wire sets? The 18-8840-1 is specific to 150 & 175 hp outboards with two 14 inch and two 16 inch wires, while other Sierra sets such as the 18-8839-1 are built for different horsepower ranges with their own wire lengths.