PRODUCT DETAILS
Cylinder Head Gasket for Mercury & Mariner 4HP–5HP 2-Stroke Outboards
Replaces Mercury Part Numbers: 27-812939015, 27-812939
This high-quality marine gasket seals the cylinder head to the engine block, maintaining compression and preventing leaks in small Mercury and Mariner 2-stroke outboards. Ideal for engine servicing, rebuilds, or preventative maintenance.
Fits the following engines:
-
Mercury 4HP 2-Stroke
-
Mercury 5HP 2-Stroke
-
Mariner 4HP 2-Stroke
-
Mariner 5HP 2-Stroke
Key Features:
-
Replaces OEM part 27-812939015
-
Built to withstand marine conditions
-
Reliable sealing performance
-
Easy installation — direct OEM-style fit
-
Perfect for small engine rebuilds or repairs
Please check compatibility before purchasing.
It is the buyer’s responsibility to confirm the correct fitment.
If you’re unsure, contact us — our SSI Marine team is happy to help.
Why Buy from SSI Marine?
-
Trusted UK supplier of marine engine parts
-
All items in stock — same-day dispatch (before 1 PM)
-
24-hour delivery
-
Expert marine support and advice
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.
YOU MIGHT ALSO LIKE
OFFICIAL PARTNERS OF
