PRODUCT DETAILS
Water Pump Service Kit for Mercury / Mariner Outboards (25HP–50HP)
High-quality aftermarket water pump service kit designed to match OEM performance.
Includes all the essential components required to restore proper cooling and water flow:
• Water pump impeller
• Upper gasket
• Lower gasket
• Woodruff key
Suitable for a wide range of Mercury and Mariner 2-stroke and 4-stroke outboards.
Ideal for routine service or impeller replacement.
Fitment – Mercury & Mariner Outboards
25 HP – 4 Stroke
• BigFoot / Command Thrust models only
30 HP & 40 HP – 4 Stroke (3-Cylinder, 3 Carburettors)
• Fits standard 3-carb 4-stroke models
• May also fit some earlier EFI 30HP & 40HP (serial number required to confirm)
30 HP & 40 HP – 2 Stroke (2-Cylinder, Single Carburettor)
50 HP – 4 Stroke (4-Cylinder, 4 Carburettors)
• Fits standard gearcase only
• Not compatible with BigFoot models
50 HP – 2 Stroke (3-Cylinder, 3 Carburettors)
• Fits late-model engines with CDM ignition coils
• Serial number check recommended if unsure
Not Compatible With
• Engines with serial numbers starting with 0N0…
If unsure, message us with your model and serial number and we will confirm the correct kit for your outboard.
Replaces Mercury OEM Part Numbers
Impeller
• 47-8508910
• 47-850893
Upper Gasket
• 27-822189
Lower Gasket
• 27-822217
Woodruff Key
• 28-85119
• 28-8M0032838
High-quality aftermarket replacements for the OEM part numbers listed above.
What’s Included
• Water pump impeller
• Upper gasket
• Lower gasket
• Woodruff key
Buyer Responsibility
Please check your engine model, year, gearcase type, and serial number before purchasing.
Mercury and Mariner engines in this HP range can use different water pump components, depending on production year and configuration.
If you’re unsure, message us — our technical team will help confirm the correct part for your engine.
For help choosing the right outboard parts, visit our guide:
https://ssimarine.co.uk/blogs/news/blogs-news-how-to-order-the-correct-outboard-parts
Return postage applies for items purchased in error or incorrect model selection.
SHIPPING & DELIVERY
Delivery & Returns Policy
Delivery
Standard Delivery
- £6: Royal Mail Tracked 24 Service
- £3.99: Large Letter - Royal Mail 1st Class Post (Untracked)
We offer free delivery on all orders over £150 (excludes outboard engines).
Orders placed before 1:00 PM (Monday-Friday) are usually dispatched the same working day.
Most parcels are delivered within 24 hours, but please allow extra time for courier delays that may occur outside our control.
For outboard engines, please contact us for a delivery quote.
Important: Please ensure your shipping address is correct before completing checkout. SSI Marine is not responsible for parcels sent to an incorrect address provided by the buyer.
Tracking Your Order
Once your order has been dispatched, you will receive a tracking number via email (after 5 PM on the day of dispatch).
Tracking is available only for parcels sent via Royal Mail Tracked 24.
Large Letter orders are sent via Royal Mail 1st Class Post (untracked).
Returns
We accept returns of unused and undamaged items within 30 days of purchase.
Returned items must be in sellable condition and include the original packaging.
Please do not tape, label, or write directly on the product's original box.
Important: Do not return items in their original product boxes only, they must be placed inside a protective outer box or bag. Parcels returned like the example below will be subject to a 20% restocking fee.
Return shipping costs are the customer's responsibility.
Please include your order details and reason for return inside the parcel.
Refunds
Refunds are issued for the item purchase price only (shipping costs are non-refundable).
All refunds will be made using the same payment method as your original order.
Items returned in poor condition or without proper packaging may incur a 20% restocking fee.
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