Ignition Coil for Mercury / Mariner OptiMax & EFI Outboards

High-quality marine-grade aftermarket 5-pin ignition coil for selected Mercury and Mariner OptiMax, EFI and Racing outboards.

Suitable for a wide range of selected 30 HP–300 HP applications where the original ignition coil cross-references to 8M0077471 / 879984T01.

Fitment

Mercury OptiMax – Selected Models

75 HP
90 HP
115 HP
125 HP
200 HP
225 HP
250 HP

Selected 75 / 90 / 115 HP 3-cylinder OptiMax applications use this coil from approximately 2004 onwards.

OptiMax Pro XS – Selected Models

115 Pro XS
175 Pro XS
200 Pro XS
225 Pro XS
250 Pro XS

OptiMax / Racing – Selected Models

225 XS
225 Sport XS
250 XS
250 Sport XS
300 XS

EFI 2-Stroke – Selected Models

150 HP – 2.5L EFI
175 HP – 2.5L EFI
200 HP – 2.5L / 3.0L EFI
225 HP – 3.0L EFI
250 HP – 3.0L EFI
Selected 225X / 300X Racing EFI

EFI 4-Stroke – Selected Applications

Also cross-referenced for selected:

30 HP
40 HP
50 HP
60 HP

⚠️ This does NOT fit every Mercury / Mariner engine within the 30–300 HP range.

Always check the original coil number and engine serial number.

Replaces Mercury / Mariner Part Numbers

300-8M0077471
8M0077471
300-879984T01
879984T01
339-879984T00
879984T00
339-879984A1
879984A1

Searchable Numbers

3008M0077471
300879984T01
339879984T00
339879984A1

Mercury identifies 8M0077471 as the superseding replacement for 879984T01, 879984T00 and 879984A1.

Product Features

5-pin connector
12V ignition coil
Mercury / Mariner applications
Selected OptiMax / Pro XS / EFI / Racing
Selected 2-stroke & 4-stroke applications
Marine-grade aftermarket replacement
Direct replacement where part number matches
New

Please Note

Replacement coils may have a different number or revision marking moulded/stamped into the body.

This is normal with superseded/replacement components and the marking alone should not be used to determine compatibility.

What's Included

1 × Ignition Coil

This listing is for ONE coil only.

⚠️ Important – Check Compatibility

Mercury used several very similar-looking ignition coils.

Before ordering, please check:

Original ignition coil part number
5-pin electrical connector
Engine horsepower
Complete serial number

If the coil looks the same as yours, this does not always mean it is the correct one for your outboard.

If unsure, send SSI Marine your engine horsepower + complete serial number + original coil number and we will help check compatibility.

Buyer Responsibility

It is the buyer's responsibility to confirm compatibility before purchasing.

Correct diagnosis is recommended before replacing ignition components, as spark plugs, wiring, trigger/stator or other electrical faults can produce similar symptoms.

Why Buy From SSI Marine?

Marine-grade aftermarket & OEM-spec parts
Workshop-tested products
More than 10 years supplying outboard parts
Same-day dispatch before 1 PM Monday–Friday
Royal Mail Tracked 24
UK stock – collection from Leigh
Technical support from experienced outboard specialists

30-300 HP Mercury Mariner Outboard OptiMax EFI Ignition Coil 8M0077471