Sierra Head Gasket 18-3847, Replaces 6L2-11181-A1-00 for Yamaha Outboard Engines

The Sierra 18-3847 is a head gasket engineered as a direct replacement for Yamaha outboard engines. It seals the cylinder head-to-block joint, maintaining proper compression and preventing coolant or combustion leaks between the head and the powerhead. Each unit is supplied as a single head gasket (quantity of 1) and is manufactured to match the original equipment specification identified by Yamaha part number 6L2-11181-A1-00.

This head gasket is designed for outboard owners and marine technicians performing a cylinder head removal, powerhead rebuild, or routine maintenance where the head gasket must be replaced to restore a proper seal. Installing a correctly specified head gasket such as the Sierra 18-3847 helps ensure consistent cylinder sealing and compression across the powerhead.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3847
• Product Type: Head Gasket
• Category: Yamaha Outboard Head Gaskets
• Quantity: 1
• Weight: 0.13 pounds
• OEM Part Number: 6L2-11181-A1-00

Fitment

Yamaha outboard engines.

Replaces (OEM)

• 6L2-W0001-01-00
• 6L2-W0001-02-00
• 6L2-W0001-A2-00
• 6L2-11181-A1-00

Frequently Asked Questions

What is the Sierra 18-3847? It is a head gasket, sold as Sierra part number 18-3847, designed to seal the cylinder head-to-block joint on Yamaha outboard engines.

What Yamaha OEM part numbers does the 18-3847 replace? The Sierra 18-3847 replaces Yamaha OEM numbers 6L2-W0001-01-00, 6L2-W0001-02-00, 6L2-W0001-A2-00, and 6L2-11181-A1-00.

How many gaskets come in one 18-3847 package? Each Sierra 18-3847 package contains a quantity of 1 head gasket.

What does the 18-3847 head gasket weigh? The Sierra 18-3847 head gasket weighs 0.13 pounds.

Is the Sierra 18-3847 a genuine Yamaha part or an aftermarket replacement? The 18-3847 is a Sierra-branded aftermarket head gasket manufactured to replace the Yamaha OEM head gasket 6L2-11181-A1-00.

What engines does the 18-3847 head gasket fit? The Sierra 18-3847 is listed for Yamaha outboard engines.

When would I need to replace the 18-3847 head gasket? This head gasket should be replaced any time the cylinder head is removed for service, or if there is a compression or coolant leak at the head-to-block joint, on the applicable Yamaha outboard engine.

Does the 18-3847 come with installation instructions or additional gaskets? The Sierra 18-3847 package includes only the head gasket itself, in a quantity of 1.

Is the Sierra 18-3847 head gasket round or a specific shape? The Sierra 18-3847 head gasket is round in shape.

Can I cross-reference the 18-3847 by its Yamaha OEM number? Yes, the Sierra 18-3847 cross-references to Yamaha OEM numbers 6L2-W0001-01-00, 6L2-W0001-02-00, 6L2-W0001-A2-00, and 6L2-11181-A1-00.