4789984T4 Mercury MerCruiser Impeller | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Water Pump Impeller - Part Number: 47-89984T4

Genuine Quicksilver/Mercury water pump impeller for selected Mercury outboard and MerCruiser Alpha One Gen I stern drive water pump assemblies. This OEM impeller is used in the lower-unit water pump to maintain correct cooling-water flow and help protect the engine from overheating.

⚙️ Key Features

• Genuine Quicksilver/Mercury OEM water pump impeller

• Used on selected MerCruiser Alpha One Gen I sterndrives and Mercury outboard gearcase water pump assemblies

• Common replacement for 89984-series Mercury impeller applications

• Helps restore cooling-water pressure and flow through the lower unit

• Direct replacement for multiple earlier Mercury 89984, 65960 and 30221 impeller references

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 47-89984T4 → Supersedes 47-89984T3

• 47-89984T3 → Supersedes 47-89984B2

• 47-89984B2 → Supersedes 47-89984

• 47-89984 earlier OEM reference

OEM / Related Numbers:

• 47-89984T4

• 89984T4

• 4789984T4

• 47-89984T3

• 89984T3

• 47-89984B2

• 89984B2

• 47-89984

• 89984

• 47-899842

• 899842

• 47-899844

• 899844

• 47-30221

• 30221

• 47-65960

• 65960

• 47-803631T

• 803631T

• 47-F694065

• F694065

Aftermarket / Verified Equivalents:

• Sierra: 18-3017

• Mallory: 9-45306

• GLM: 89840

• SEI: 96-102-03

• SEI: 96-102-06K

🚤 Compatibility

Commonly used on:

• MerCruiser Alpha One Gen I stern drive water pump assemblies

• Mercury / Mariner larger outboard lower-unit water pump assemblies

• Mercury OptiMax 2.5L non-Pro outboard water pump applications

Typically suits:

• Engine models:

• MerCruiser Alpha One Gen I stern drives, approximately 1983-1990

• Mercury 65HP, serial range 2803562 - 3293183

• Mercury 75HP 3-cylinder, serial 6432901 and up

• Mercury 75HP 4-cylinder, serial 6432901 and up

• Mercury 80HP, serial range 2559001 - 3493912

• Mercury 85HP 4-cylinder, serial range 3493913 - 4831998

• Mercury 90HP, serial range 1766824 - 1869775

• Mercury 90HP, serial range 5299506 - 5594656

• Mercury 90HP 6-cylinder, serial 4845301 and up

• Mercury 1150 / 115HP, serial range 2836019 - 3525440

• Mercury 125HP, serial range 2314956 - 2839368

• Mercury 1500XS / 150HP, serial range 4868648 - 5327662

• Mercury OptiMax 2.5L non-Pro outboards, serial 1B227000 and up

• HP Range: Approximately 65HP - 150HP for listed conventional Mercury outboard applications, plus selected Mercury OptiMax 2.5L non-Pro models and MerCruiser Alpha One Gen I sterndrives

• Engine Type: Mercury / Mariner outboard and MerCruiser stern drive lower-unit water pump system

• Year Range: Application dependent; Alpha One Gen I commonly 1983-1990, outboard fitment by serial range

🔌 Function

The impeller rotates inside the water pump housing to draw water through the gearcase or stern drive and push it through the engine cooling system. Correct impeller condition is essential for stable cooling flow, water pressure and engine temperature control.

Common signs of failure:

• Weak or inconsistent tell-tale water stream

• Engine overheating alarm

• Reduced water pressure

• Overheating at idle, low speed or under load

• Cracked, hardened, curled or missing impeller vanes

• Rubber fragments found in the cooling system

• Water pump not priming correctly after service or storage

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging