# 25-627021 Mercury MerCruiser O-Ring | Genuine Quicksilver OEM Part

🔧 Product Description

  

Genuine Quicksilver Temperature Sensor O-Ring - Part Number: 25-627021

  

A genuine Quicksilver O-ring used on Mercury, Mariner and MerCruiser temperature sensor / sender sealing locations. This .301" x .070" O-ring replaces earlier 25-62702 and is commonly used across selected 20HP to 400HP Mercury / Mariner outboards and MerCruiser petrol engines where specified.

  

⚙️ Key Features

  

• Genuine Quicksilver OEM O-ring

• Correct Mercury part number 25-627021

• Supersedes 25-62702

• .301" x .070" O-ring size

• Commonly used on temperature sensor / sender assemblies

• Cross-references with WSM 526-08 temperature sensor O-ring applications

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 25-627021 → Supersedes 25-62702

• 25-62702 earlier OEM O-ring reference

• F50342 earlier Force / Mercury reference where specified

  

OEM / Related Numbers:

  

• 25-627021

• 627021

• 25-62702

• 62702

• F50342

• Mercury 25-627021

• Quicksilver 25-627021

• Temperature sensor O-ring

• Sender O-ring

• .301 x .070 O-ring

  

Aftermarket / Verified Equivalents:

  

• WSM: 526-08

• WSM: 526-08A1

• Aftermarket temperature sensor O-ring equivalents exist where matched to 25-627021 / 25-62702

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury / Mariner temperature sensor and sender locations

• MerCruiser temperature sensor and sender locations

• Small O-ring sealing points where 25-627021 is specified

  

Typically suits:

  

• Engine models:

• Mercury / Mariner 20HP outboard temperature sensor applications where 25-627021 is specified

• Mercury / Mariner 25HP outboard temperature sensor applications where 25-627021 is specified

• Mercury / Mariner 40HP outboard temperature sensor applications where 25-627021 is specified

• Mercury / Mariner 50HP outboard temperature sensor applications where 25-627021 is specified

• Mercury / Mariner 60HP FourStroke / EFI applications where 25-627021 is specified

• Mercury / Mariner 75HP through 300HP outboard sensor sealing applications where specified

• Mercury 400HP outboard sensor sealing applications where 25-627021 is specified

• MerCruiser 350 Scorpion - serial 0W698433 and up where O-ring 25-627021 is specified

• MerCruiser Scorpion 350 EC - serial 0W698433 and up where specified

• MerCruiser Scorpion 377 - serial 0W698433 and up where specified

• MerCruiser Scorpion 377 HO EC - serial 1A091488 to 1A092170 where specified

• MerCruiser petrol engine temperature sensor / sender applications using O-ring 25-627021

  

• HP Range: commonly 20HP - 400HP outboard applications where specified, plus MerCruiser petrol engines where specified

• Engine Type: Mercury / Mariner outboard and MerCruiser petrol engine

• System Type: Temperature sensor / sender O-ring

• O-Ring Size: .301" x .070"

  

🔌 Function

  

The O-ring seals the temperature sensor or sender to prevent water, coolant or fluid leakage around the sensor body while maintaining the correct sensor seating depth.

  

Common signs of failure:

  

• Water or coolant seepage around temperature sensor

• O-ring flattened, cut or swollen

• Sensor removed and O-ring disturbed

• Corrosion around sensor bore

• Temperature sensor service requiring reseal

• Incorrect O-ring causing sensor leak or poor fit

  

📦 Condition

  

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 2.8 AUD
- **Vendor:** Quicksilver
- **Tags:** Quicksilver Marine Parts | Oils Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 2.80 AUD | In stock |

## Images

- 25-627021 Mercury MerCruiser O-Ring | Genuine Quicksilver OEM Part
- 25-627021 Mercury MerCruiser O-Ring | Genuine Quicksilver OEM Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/25-627021-mercury-mercruiser-o-ring-genuine-quicksilver-oem-part)
> Updated: 2026-07-18