478M0204712 Mercury MerCruiser Impeller | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Water Pump Impeller - Part Number: 47-8M0204712

Genuine Quicksilver/Mercury water pump impeller for selected Mercury and Mariner 15HP-25HP outboard lower-unit water pump applications. This OEM impeller replaces earlier 85089-series Mercury impeller references and helps restore proper cooling-water flow through the gearcase pump.

⚙️ Key Features

• Genuine Quicksilver/Mercury OEM water pump impeller

• Designed for selected Mercury / Mariner 15HP-25HP outboards

• Direct replacement for earlier 85089-series impeller references

• Used in compatible lower-unit water pump assemblies

• Helps restore tell-tale flow, cooling-water pressure and pump priming

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 47-8M0204712 → Supersedes 47-8M0027792

• 47-8M0027792 → Supersedes 47-8M0024502

• 47-8M0024502 → Supersedes 47-850893

• 47-850893 → Supersedes 47-8508920

• 47-8508920 → Supersedes 47-8508910

• 47-8508910 → Supersedes 47-850891

• 47-850891 → Supersedes 47-85089

• 47-85089 earlier OEM reference

OEM / Related Numbers:

• 47-8M0204712

• 8M0204712

• 478M0204712

• 47-8M0027792

• 8M0027792

• 47-8M0024502

• 8M0024502

• 47-850893

• 850893

• 47-8508920

• 8508920

• 47-8508910

• 8508910

• 47-850891

• 850891

• 47-85089

• 85089

Aftermarket / Verified Equivalents:

• REC: REC47-85089

• Sierra: 18-3099 where matched by pump dimensions and application

• Mallory: 9-45310 where matched by pump dimensions and application

🚤 Compatibility

Commonly used on:

• Mercury / Mariner 15HP-25HP outboard lower-unit water pump assemblies

• Small-to-mid Mercury / Mariner outboard gearcase cooling systems using the 85089-series impeller

Typically suits:

• Engine models:

• Mercury / Mariner 15HP 2-Stroke outboard applications using 85089-series water pump impeller

• Mercury / Mariner 18HP 2-Stroke outboard applications using 85089-series water pump impeller

• Mercury / Mariner 20HP 2-Stroke outboard applications using 85089-series water pump impeller

• Mercury / Mariner 25HP 2-Stroke outboard applications using 85089-series water pump impeller

• Mercury / Mariner 15HP-25HP small outboard gearcase applications where the parts diagram specifies 47-8M0204712

• Mercury / Mariner 15HP-25HP service applications replacing 47-85089, 47-850891, 47-8508910, 47-8508920, 47-850893, 47-8M0024502 or 47-8M0027792

• HP Range: 15HP - 25HP

• Engine Type: Mercury / Mariner outboard lower-unit water pump system

• Year Range: Application dependent by model and serial number; confirm against the gearcase water pump parts diagram when replacing earlier 85089-series impellers

🔌 Function

The impeller draws water through the lower unit and pushes it into the engine cooling system. A correct impeller helps maintain water pressure, reduces overheating risk and supports reliable cooling at idle, low speed and operating RPM.

Common signs of failure:

• Weak or inconsistent tell-tale water stream

• Engine overheating warning

• Pump not priming after service

• Cracked, stiff or missing impeller vanes

• Reduced cooling-water pressure

• Rubber fragments found in the cooling system

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging