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

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

This head and cover gasket set is designed for Johnson/Evinrude 18, 20, 25, 28, 30, and 35 HP 2-stroke outboard engines manufactured between 1979 and 2001.

It serves as a direct replacement for Johnson/Evinrude part numbers 327674, 324324, 329419, and 765012, as well as Sierra aftermarket parts 18-3899 and 18-3803.

• Engineered for a direct fit, ensuring a reliable seal.
• Manufactured from high-quality materials to meet or exceed OEM specifications.
• Provides essential components for cylinder head and cover repairs.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.

Technical Specifications

Package Contents

1 x Head and Cover Gasket Set (Replaces 765012, 327674)

Installation Guide

1. Safety First: Disconnect the battery and spark plug wires before beginning work.
2. Drain Fluids: Drain the engine coolant completely to avoid spills.
3. Access the Head: Remove the engine cover and any components obstructing access to the cylinder head bolts.
4. Remove Head Bolts: Carefully loosen and remove the cylinder head bolts. Follow the reverse of the manufacturer's tightening sequence.
5. Lift the Head: Gently lift the cylinder head off the engine block. Avoid using pry bars that could damage the mating surfaces.
6. Clean Surfaces: Remove the old gasket. Thoroughly clean both the cylinder head and engine block surfaces until they are free of any old gasket material or debris.
7. Position New Gasket: Place the new head and cover gaskets correctly onto the engine block.
8. Reinstall Head: Carefully place the cylinder head back onto the block and install the head bolts.
9. Torque Bolts: Torque the head bolts to the manufacturer's specified values using the correct tightening sequence to ensure an even seal.
10. Reassemble: Reinstall all previously removed components.
11. Refill and Check: Refill the engine with coolant, then reconnect the spark plug wires and battery.
12. Test: Start the engine and carefully check for any coolant, fuel, or exhaust leaks around the gasket area.

Troubleshooting & FAQ

How do I confirm this gasket set fits my engine?
This set is specifically for Johnson/Evinrude 18-35 HP, 2-stroke outboards made between 1979 and 2001. The best way to confirm fitment is to match your engine's original part number to the ones listed here: OEM (765012, 327674) or Sierra (18-3899, 18-3803).

What are the signs that my head gasket needs replacing?
Common symptoms of a failed head gasket include engine overheating, a noticeable loss of power or compression, milky or discolored oil, and white smoke coming from the exhaust.

Is everything I need for the job included?
This package contains the head and cover gasket set. Please review the product images and the 'Package Contents' section to ensure it includes all parts necessary for your specific repair, as other seals or gaskets may be required.

OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.