Regulator / Rectifier for Mercury Mariner Outboards

High-quality marine-grade aftermarket regulator / rectifier for selected Mercury and Mariner 15 HP and 20 HP 4-stroke EFI outboard engines.

Designed as a replacement for Mercury / Mariner:

8M0134477

Suitable for selected later-generation Electronic Fuel Injection (EFI) models with serial numbers in the 0R... family.

Fits Selected Mercury Mariner 4-Stroke EFI Outboards

15 HP

Selected:

15 HP 4 Stroke EFI

Electronic Fuel Injection – EFI
Selected engines with serial numbers beginning 0R...
Later-generation 15 HP 4-stroke applications

20 HP

Selected:

20 HP 4 Stroke EFI

Electronic Fuel Injection – EFI
Selected engines with serial numbers beginning 0R...
Later-generation 20 HP 4-stroke applications

Replaces Mercury / Mariner Part Number

8M0134477

Also searchable as:

8M0134477
8M0134477 Rectifier
8M0134477 Regulator
8M0134477 Regulator Rectifier

EFI Models

This regulator / rectifier is intended for selected later Mercury / Mariner:

15 HP EFI

20 HP EFI

4-stroke outboards.

EFI = Electronic Fuel Injection

This is important because Mercury / Mariner used a different rectifier on earlier carburettor 15 HP and 20 HP 4-stroke engines.

⚠️ EFI vs Carburettor – Important

Mercury / Mariner 15 HP and 20 HP 4-stroke engines can use different rectifiers depending on the engine generation.

Later EFI Models

8M0134477

Suitable for selected later:

15 HP EFI
20 HP EFI
4 Stroke
0R... serial-number family

Earlier Carburettor Models

Earlier carburettor 15 HP / 20 HP engines can use:

879147T62

These parts should NOT be selected by horsepower alone.

Please identify whether your engine is EFI or carburettor and check the original part number before ordering.

Product Features

Marine-grade aftermarket regulator / rectifier
Suitable for selected Mercury outboards
Suitable for selected Mariner outboards
15 HP EFI
20 HP EFI
4-stroke applications
Electronic Fuel Injection
Selected 0R... serial-number engines
Replacement for 8M0134477
Designed for the applicable Mercury / Mariner charging system
Direct replacement for compatible applications
No assembly required
New aftermarket replacement component

⚠️ Important – Serial Number

Mercury / Mariner parts are frequently determined by engine serial number, not simply horsepower and year.

This part is used on selected engines within the 0R... serial-number family, but:

A serial number beginning 0R does NOT by itself guarantee fitment.

Before purchasing, please check:

Exact horsepower
4-stroke engine
EFI – Electronic Fuel Injection
Complete engine serial number
Original regulator / rectifier part number
Electrical connector
Wiring configuration
Mounting arrangement

Ideally, match your original part number to:

8M0134477

⚠️ Important – Check Before Ordering

Do NOT order this regulator / rectifier simply because:

Your engine is 15 HP
Your engine is 20 HP
Your serial number starts with 0R
The regulator looks the same

Mercury / Mariner used different electrical components across different engine generations.

Please double-check the complete engine details before purchasing.

⚠️ Appearance Does Not Confirm Fitment

If the regulator / rectifier looks the same as the one fitted to your engine, this does not always mean it is the correct part for your outboard.

Different Mercury / Mariner charging-system components can look very similar while having different electrical specifications.

If you are unsure, contact SSI Marine with your complete engine serial number before purchasing.

Before Installing Your New Regulator / Rectifier

If your original regulator / rectifier has failed, we recommend checking the complete charging system before installing the replacement.

Check:

AC output from the stator
Battery condition
Battery terminals
Engine earth / ground connections
Stator wiring
Fuse and fuse holder
Electrical plugs and connectors
Burnt or corroded terminals
Melted or heat-damaged wiring

Any charging-system faults or damaged electrical connections should be repaired before installing the replacement unit.

Suitable high-temperature dielectric grease can be used on applicable electrical connectors.

Aftermarket Replacement Part

This is a high-quality marine-grade aftermarket replacement part.

It is not a genuine Mercury or Mariner component.

OEM manufacturer names and part numbers are provided for identification and compatibility reference only.

The component is designed as a replacement for compatible Mercury / Mariner applications using 8M0134477.

Buyer Responsibility

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

Please check:

Mercury / Mariner engine
15 HP or 20 HP
4 Stroke
EFI specification
Complete serial number
Original part number
Electrical connections

If you are unsure, contact SSI Marine before ordering. Our technical team will be happy to help identify the correct component.

Why Buy From SSI Marine?

Marine-grade aftermarket & OEM-spec parts
Workshop-tested products
More than 10 years supplying and working with outboard engines
Same-day dispatch before 1 PM Monday–Friday
Royal Mail Tracked 24
UK stock
Collection available from Leigh, Greater Manchester
Technical support from experienced outboard specialists
Workshop open Monday–Friday, 9 AM–5 PM

15 HP 20 HP Mercury Mariner Outboard 4 Stroke EFI Regulator Rectifier 8M0134477