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

Cylinder Head Gasket for Mercury Mariner 4HP–5HP 2-Stroke Outboard | Replaces 27-812939015