Water Pump Repair Kit for Mercury Mariner 25 50 HP Outboard 821354A04 18 4531
Available to Order
Need help finding the right part? Talk with a parts expert today.
Parts Support Hours: Monday–Friday, 8:00 AM–5:00 PM CT
Live Chat: Available 24/7
I needed a forklift part and wasn’t sure which one fit. They asked for the model and serial number, got back to me quickly, and made sure I ordered the right one. Really helpful.
Randy W. — Verified customer
Product Overview
Key Features & Performance
- Includes all necessary gaskets and seals for water pump replacement
- Direct fit for Mercury/Mariner 25-50 HP outboards
- Replaces OEM part numbers 821354A04 and 18-4531
- Helps maintain proper engine cooling and prevent overheating
- High-quality materials for reliable performance
Fitment & Compatibility
- Mercury Outboard 25-50 HP
- Mariner Outboard 25-50 HP
- Replaces OEM Part #821354A04, 18-4531
Common Uses
- Replacing worn or failed water pump in outboard motors
- Performing routine maintenance on Mercury/Mariner engines
- Restoring cooling efficiency for extended engine life
- Preventing overheating during operation
Technical Specifications
- Part Number(s): 821354A04, 18-4531
- Engine Compatibility: Mercury/Mariner 25-50 HP
Frequently Asked Questions
Q: Is this kit compatible with a 2000 Mercury 40 HP? A: Yes, this water pump repair kit fits Mercury and Mariner outboards from 25 to 50 HP, including the 40 HP model.
Q: Does the kit include the impeller? A: Yes, the water pump repair kit typically includes an impeller, gaskets, and seals for a complete rebuild. Check the product listing for exact contents.
Product appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.