# 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part

🔧 Product Description

  

Genuine Quicksilver Water Pump Impeller Key - Part Number: 28-8M0204723

  

Genuine Quicksilver impeller key used in Mercury / Mariner water pump assemblies. This key locks the impeller to the driveshaft so the impeller turns correctly inside the pump housing.

  

⚙️ Key Features

  

• Genuine Quicksilver OEM impeller key

• Correct Mercury part number 28-8M0204723

• Current replacement for earlier 28-16173 in supported diagrams

• Used in lower-unit water pump assemblies

• Critical replacement item during impeller service if missing or worn

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 28-8M0204723 current OEM impeller key reference

• 28-16173 earlier related impeller key reference

  

OEM / Related Numbers:

  

• 28-8M0204723

• 8M0204723

• 288M0204723

• 28-16173

• 16173

• Impeller key

• Water pump key

• Driveshaft impeller key

• 47-8M0204712 related impeller family

• 46-8M0122064 related water pump kit family

  

Aftermarket / Verified Equivalents:

  

• Aftermarket impeller key equivalents for 28-16173 / 28-8M0204723 applications

• Sierra / GLM / WSM water pump kits may include a matching impeller key where the kit covers the same pump assembly

• Match the key profile to the exact impeller and driveshaft slot

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury / Mariner lower-unit water pump assemblies

• Mercury 30HP to 125HP pump stacks where 28-8M0204723 is specified

• Water pump service where the impeller key is removed or damaged

  

Typically suits:

  

• Engine models:

• Mercury 30HP outboard water pump applications where 28-8M0204723 is specified

• Mercury 40HP outboard water pump applications where specified

• Mercury 50HP outboard water pump applications where specified

• Mercury 60HP outboard water pump applications where specified

• Mercury 70HP through 125HP water pump applications where specified

• Mercury 75 DFI / OptiMax 1.5L pump assemblies where specified

• Mercury 90 DFI / OptiMax 1.5L pump assemblies where specified

• Mercury 115 DFI / OptiMax 1.5L pump assemblies where specified

• Mariner matching 30HP to 125HP lower-unit water pump assemblies where specified

  

• HP Range: commonly 30HP - 125HP where specified

• Engine Type: Mercury / Mariner outboard

• System Type: Water pump impeller key

  

🔌 Function

  

The key locks the impeller to the driveshaft so the impeller rotates with the shaft and creates cooling-water flow.

  

Common signs of failure:

  

• Impeller spins freely on driveshaft

• Weak or no cooling water output

• Key missing after impeller removal

• Key worn, corroded or sheared

• Pump rebuilt but impeller not driving

• Replacement required during impeller service

  

📦 Condition

  

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 6.15 AUD
- **Vendor:** Quicksilver
- **Tags:** Quicksilver Marine Parts | Oils Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 6.15 AUD | In stock |

## Images

- 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part
- 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part
- 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part
- 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part
- 8M0204723 Mercury MerCruiser 28 8M0204723 Impeller Key | Genuine Quicksilver OEM Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/8m0204723-mercury-mercruiser-28-8m0204723-impeller-key-genuine-quicksilver-oem-part)
> Updated: 2026-07-18