Sierra 18-5225 Spark Plug Wire Kit, 25 Foot Hypalon Ignition Wire, Replaces Mercury 84-99215A26, 84-813706A26

The Sierra 18-5225 Spark Plug Wire Kit gives you everything needed to rebuild the ignition wiring on outboard motors that use Mercury-style spark plug wire. Rather than a fixed-length pre-terminated wire, the kit is built around a 25 foot roll of 7mm Hypalon ignition wire with a metallic core, paired with a large assortment of three different end fittings so you can cut the wire to the exact length each cylinder requires and terminate it with the correct fitting for your engine. This makes the kit useful for replacing cracked, brittle, or misfiring ignition wires on multi-cylinder outboards without having to source individual pre-made leads.

The Hypalon jacket is a synthetic rubber compound chosen for its resistance to heat, oil, and the harsh marine environment, while the metallic core is designed to carry ignition voltage reliably to the spark plugs. Because the kit supplies bulk wire and multiple fitting sizes rather than one fixed harness, it is well suited to shops and owners who need to service more than one cylinder or more than one engine from a single kit. The Sierra 18-5225 directly replaces Mercury ignition wire kits 84-99215A26 and 84-813706A26.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5225
• Product Type: Spark Plug Wire Kit
• Wire Length: 25 feet
• Wire Diameter: 7 millimeters
• Wire Material: Hypalon jacket with metallic core
• End Fittings: Large assortment of three different sizes to fit outboard motors
• Weight: 0.55 pounds

Fitment

Designed to fit outboard motors that use the Mercury ignition wire kits listed below.

Replaces (OEM)

• Mercury 84-99215A26
• Mercury 84-813706A26

Frequently Asked Questions

What does the Sierra 18-5225 Spark Plug Wire Kit include? The kit includes a 25 foot roll of 7mm Hypalon ignition wire with a metallic core, plus a large assortment of three different end fittings so you can build wires to fit outboard motors.

What size is the ignition wire in this kit? The wire supplied in the Sierra 18-5225 kit is 7 millimeters in diameter and comes as a 25 foot roll, letting you cut leads to the length each cylinder needs.

What is the wire jacket made of? The 18-5225 kit uses 7mm Hypalon ignition wire with a metallic core, a synthetic rubber jacket chosen for durability in the marine environment.

Which OEM part numbers does the Sierra 18-5225 replace? This kit replaces Mercury ignition wire kits 84-99215A26 and 84-813706A26.

Will this kit fit my specific outboard motor? The Sierra 18-5225 is built to fit outboard motors that originally used Mercury ignition wire kits 84-99215A26 or 84-813706A26; the assortment of three end fitting sizes is provided to match different outboard applications.

Does the kit come with pre-cut, terminated wires? No. The 18-5225 supplies a 25 foot roll of bulk 7mm Hypalon ignition wire along with an assortment of end fittings, so wires are cut and terminated to the length and fitting needed for each cylinder.

How much wire is in the Sierra 18-5225 kit? There are 25 feet of 7mm Hypalon ignition wire included in the kit, enough to build multiple spark plug leads.

How many end fitting sizes come with the kit? The Sierra 18-5225 includes a large assortment of three different end fitting sizes to fit outboard motors.

How much does the Sierra 18-5225 kit weigh? The kit weighs 0.55 pounds.

Is the Sierra 18-5225 an OEM Mercury part or an aftermarket replacement? It is a Sierra aftermarket kit engineered to replace Mercury ignition wire kits 84-99215A26 and 84-813706A26.

Can this kit be used on more than one cylinder or engine? Because the 18-5225 provides a full 25 foot roll of wire and multiple end fitting sizes rather than a single pre-made lead, it can be used to service more than one cylinder or spark plug wire from a single kit.