Cylinder Head Gasket Set – Fits Johnson/Evinrude 18-35 HP (Replaces 765012, 327674)

$19.95

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Cylinder Head Gasket Set – Fits Johnson/Evinrude 18-35 HP (Replaces 765012, 327674) is backordered and will ship as soon as it is back in stock.

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Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Cylinder Head Gasket Set is designed for 2-cylinder Johnson and Evinrude outboard motors ranging from 18 to 35 HP, covering model years from 1979 to 2005. The kit provides the essential gaskets needed to seal the engine head and water cover during maintenance or rebuilds.

It directly replaces Johnson/Evinrude OEM part numbers 765012, 324324, 327674, and 329419, and serves as an interchange for Sierra 18-3803, 18-3899, GLM 34570, and Mallory 9-63830.

Engineered for 2-cylinder, 2-stroke gasoline outboards.
Installs between the engine head and cylinder block, and on the water jacket cover.
Includes both head gaskets and water cover gaskets for a complete service.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number	Notes
Johnson/Evinrude	765012	OEM Gasket Set
Johnson/Evinrude	324324	OEM Head Gasket
Johnson/Evinrude	327674	OEM Water Cover Gasket
Johnson/Evinrude	329419	OEM Head Gasket (Supersession)
Sierra	18-3803	Aftermarket Gasket Set
Sierra	18-3899	Aftermarket Water Cover Gasket
GLM	34570	Aftermarket Gasket Set
Mallory	9-63830	Aftermarket Gasket Set

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This set fits various Johnson outboard models from 18 HP to 35 HP produced between 1979 and 2005.

It is also compatible with Evinrude outboards in the same 18 HP to 35 HP range with model years from 1979 to 2005, depending on the specific model.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Johnson	Outboard	18	2-Stroke	1995–1998	765012, 324324	Jet models
Johnson	Outboard	20	2-Stroke	1979–2003	765012, 324324	2-cylinder models
Johnson	Outboard	25	2-Stroke	1979–2003	765012, 324324	2-cylinder models
Johnson	Outboard	25C	2-Stroke	1997–2005	765012, 324324	Commercial models
Johnson	Outboard	28	2-Stroke	1986–1996	765012, 324324	2-cylinder models
Johnson	Outboard	30	2-Stroke	1984–2003	765012, 324324	2-cylinder models
Johnson	Outboard	35	2-Stroke	1979–1988	765012, 324324	2-cylinder models
Evinrude	Outboard	18	2-Stroke	1995–1998	765012, 324324	Jet models
Evinrude	Outboard	20	2-Stroke	1979–2001	765012, 324324	2-cylinder models
Evinrude	Outboard	25	2-Stroke	1979–2001	765012, 324324	2-cylinder models
Evinrude	Outboard	25C	2-Stroke	1997–2005	765012, 324324	Commercial models
Evinrude	Outboard	28	2-Stroke	1986–1996	765012, 324324	2-cylinder models
Evinrude	Outboard	30	2-Stroke	1984–2001	765012, 324324	2-cylinder models
Evinrude	Outboard	35	2-Stroke	1979–1988	765012, 324324	2-cylinder models

Technical Specs

Product Type: Cylinder Head Gasket Set
Installation: Engine Head and Cover
Fuel Type: Gasoline
Housing Material: Composite
Other Technical Attributes: Fits 2-cylinder models

What’s in the Box

2 x Head Gasket (Replaces 324324/329419)
2 x Water Cover Gasket (Replaces 327674/33700)

Installation Notes

Ensure the engine is off, cool, and disconnected from the power source. Disconnect the fuel line.
Carefully remove the engine cowling and any other components obstructing access to the cylinder head and water cover.
Unbolt and remove the water cover and cylinder head, following the manufacturer's recommended torque sequence in reverse.
Thoroughly clean all mating surfaces on the engine block, head, and cover. Remove all traces of old gasket material and debris.
Place the new gaskets into position on the clean surfaces. Ensure they are correctly aligned with all bolt holes and passages.
Reinstall the cylinder head and water cover. Tighten the bolts in the specific sequence and to the torque values specified in your engine's service manual.
Reconnect all components, fuel lines, and electrical connections. Reinstall the engine cowling before testing.

Troubleshooting & FAQ

How do I know if this gasket set fits my specific engine?

Verify your engine's model, HP, and year against the compatibility table. This set is for 2-cylinder Johnson and Evinrude outboards from 18 to 35 HP (1979–2005). Always cross-reference the OEM part number (e.g., 765012) for the most accurate fitment.

What are the signs of a failed head gasket?

Common symptoms include engine overheating, a noticeable loss of power or compression, water in the cylinders or spark plugs, milky-looking oil, or excessive white steam from the exhaust once the engine is warm.

Does this kit contain everything for my 2-cylinder engine?

Yes. This kit includes two head gaskets and two water cover gaskets, providing a complete set for servicing both cylinders on compatible Johnson and Evinrude motors.

When should these gaskets be replaced?

Gaskets should be replaced any time the cylinder head is removed for service, during a complete engine rebuild, or if symptoms of a gasket failure are present. They are designed for a single use and should not be reinstalled.

Is this an OEM part or an aftermarket replacement?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials and manufactured in an ISO 9002 facility, with batch inspections for consistency.

What are the shipping speed and cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free, and expedited options will appear at checkout where available.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, contact our support team with your order details. Returns are accepted within our standard window, provided the item is unused and in its original condition. See our policy page or reach out for instructions.

Safety & Important Info

Verify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement component, not an OEM part.
Professional installation is recommended for safety and optimal performance.

About Sea Sierra

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