Sierra 18-99060 Head Gasket - Replaces Yamaha 63D-11181-A0-00 for 40/50/C40/C50/P40/P50 Outboards

The Sierra 18-99060 Head Gasket is a cylinder head gasket engineered as a direct replacement for Yamaha outboard engines. It seals the mating surface between the cylinder head and the powerhead block, maintaining compression and preventing coolant or combustion leakage that can lead to overheating or loss of power. Each Sierra gasket is manufactured to meet or exceed the specification of the original equipment part it replaces, making it a reliable choice for engine rebuilds, head removal service, or routine maintenance on covered Yamaha outboard models.

This head gasket fits Yamaha 40 hp (1995-2006), 50 hp (1995-2009), C40 (1998-2003), C50 (1998-2001), P40 (1998), and P50 (1995-1996) outboard engines, and is interchangeable with Yamaha Outboard part numbers 63D-11181-A0-00, 63D-11181-A1-00, and 63D-11181-A2-00. The package includes one head gasket. As with any head gasket installation, proper torque sequence and specification should be followed to ensure a lasting seal.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99060
• Product Type: Head Gasket
• Included Components: Gasket, Head
• Unit Count: 1 Count
• Weight: 0.24 pounds
• UPC: 808282293758

Fitment

• Yamaha 40 hp (1995-2006)
• Yamaha 50 hp (1995-2009)
• Yamaha C40 (1998-2003)
• Yamaha C50 (1998-2001)
• Yamaha P40 (1998)
• Yamaha P50 (1995-1996)

Replaces (OEM)

• 63D-11181-A0-00
• 63D-11181-A1-00
• 63D-11181-A2-00

Frequently Asked Questions

What engines does the Sierra 18-99060 head gasket fit? It fits Yamaha 40 hp (1995-2006), 50 hp (1995-2009), C40 (1998-2003), C50 (1998-2001), P40 (1998), and P50 (1995-1996) outboard engines.

Is the 18-99060 gasket a genuine Yamaha part or aftermarket? The 18-99060 is a Sierra-manufactured head gasket built to meet or exceed the original equipment specification, offered as an aftermarket replacement rather than a Yamaha-branded part.

Which Yamaha OEM part numbers does 18-99060 replace? Sierra 18-99060 is interchangeable with Yamaha Outboard 63D-11181-A0-00, 63D-11181-A1-00, and 63D-11181-A2-00.

How much does the head gasket weigh? The Sierra 18-99060 head gasket weighs 0.24 pounds.

How many gaskets come in one package? One 18-99060 head gasket is included per unit, listed as a 1 Count package.

Does 18-99060 fit the Yamaha 50 hp made in every year? It is designated for the Yamaha 50 hp covering the 1995-2009 range; confirm your engine falls within that span before ordering.

Will this gasket work on a Yamaha C40 or C50? Yes, the 18-99060 head gasket covers the Yamaha C40 (1998-2003) and C50 (1998-2001) models in addition to the standard 40 and 50 hp engines.

Is a warranty included with the 18-99060 head gasket? Sierra parts, including the 18-99060 head gasket, are covered under Sierra's standard customer satisfaction warranty.

What is included in the box with part number 18-99060? The package contains the head gasket itself; no additional hardware or seals are listed as included components.

Does the P40 or P50 Yamaha outboard use this same gasket? Yes, Sierra 18-99060 is fitted for the Yamaha P40 (1998) and P50 (1995-1996) models as well.