Sierra Ignition Wire Set 18-8804-1 for MerCruiser 260 350 MAG and 300 320 EFI 350 V-8 Electronic Distributor

The Sierra 18-8804-1 is an ignition wire set built for MerCruiser stern drive and inboard V-8 engines equipped with a standard-rotation electronic distributor. It supplies the coil lead and spark plug leads needed to deliver a reliable spark path from the distributor to each cylinder, and it is designed for electronic distributor ignition systems, excluding Thunderbolt ignition setups. The set includes one coil lead measuring 12 inches along with spark plug leads in four lengths (30, 35, 40, and 45 inches) so each cylinder position gets a properly sized lead rather than a one-size-fits-all wire. Leads use lead-based conductor construction typical of marine ignition wiring for consistent conductivity and resistance to the vibration and heat found in an engine compartment.

This wire set fits MerCruiser 260 and 350 MAG V-8 engines built in the 1982-1994 model years within serial number range 6218462 through F600999, as well as MerCruiser 300 and 320 EFI 350/V-8 engines built in the 1985-1989 model years within serial number range A543604 through C622418. Confirm your engine model and serial number against these ranges before ordering, since ignition wiring is engine-specific and the wrong set will not seat or route correctly.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8804-1
• Product Type: Ignition wire set (wiring and plug set)
• Ignition Compatibility: Electronic distributor, standard rotation, excluding Thunderbolt ignition
• Coil Lead Length: 12 inches (1 lead)
• Spark Plug Lead Lengths: 30 inches, 35 inches, 40 inches, 45 inches (2 leads each length)
• Material: Lead
• Item Dimensions: 2.75 x 7.12 x 10.5 inches
• Weight: 1.94 pounds

Fitment

• MerCruiser 260, 350 MAG V-8, 1982-1994, serial number range 6218462 - F600999
• MerCruiser 300, 320 EFI 350/V-8, 1985-1989, serial number range A543604 - C622418

Frequently Asked Questions

What engines does the Sierra 18-8804-1 ignition wire set fit? This wire set fits MerCruiser 260 and 350 MAG V-8 engines from the 1982-1994 model years within serial number range 6218462 through F600999, and MerCruiser 300 and 320 EFI 350/V-8 engines from the 1985-1989 model years within serial number range A543604 through C622418.

Will 18-8804-1 work with a Thunderbolt ignition system? No. The Sierra 18-8804-1 is built for standard-rotation electronic distributor ignition and specifically excludes Thunderbolt ignition systems, so it should not be used on engines with Thunderbolt ignition.

How many spark plug leads come in this set, and how long are they? The 18-8804-1 set includes spark plug leads in four lengths: 30 inches, 35 inches, 40 inches, and 45 inches, with two leads supplied at each length to cover a V-8 cylinder layout.

Does the kit include a coil lead? Yes, the Sierra 18-8804-1 includes one coil lead measuring 12 inches in addition to the spark plug leads.

What material are the ignition leads made of? The leads in the 18-8804-1 wire set use lead-based conductor construction, which is standard for marine ignition wiring exposed to engine heat and vibration.

How much does the 18-8804-1 wire set weigh? The Sierra 18-8804-1 ignition wire set weighs 1.94 pounds.

What are the packaged dimensions of this ignition wire set? The Sierra 18-8804-1 measures 2.75 x 7.12 x 10.5 inches as packaged.

How do I know if my MerCruiser engine is in the right serial number range for this part? Check your engine's serial number tag against the ranges listed for the 18-8804-1: 6218462 through F600999 for the 260/350 MAG V-8, or A543604 through C622418 for the 300/320 EFI 350/V-8. If your serial number falls outside both ranges, this part is not the correct match.

Is this a full ignition wire set or just replacement plug wires? The 18-8804-1 is a complete wiring and plug lead set, including both the coil lead and the full set of spark plug leads needed for the engine, not a single replacement wire.

Can this wire set be used on engines outside the listed serial number ranges? Fitment for the Sierra 18-8804-1 is defined by the specific engine models and serial number ranges listed, so it should only be used on MerCruiser 260/350 MAG or 300/320 EFI 350/V-8 engines that fall within those ranges.