Head and Cover Gasket Set – Fits Johnson/Evinrude 18-35 HP Outboards
This head and cover gasket set is designed for Johnson/Evinrude 2-stroke outboard engines in the 18-35 HP range manufactured between 1979 and 2001. It is manufactured from OEM-spec materials to ensure a reliable, direct replacement fit.
This kit provides direct replacements for Johnson/Evinrude part numbers 327674, 324324, 329419, and 765012, along with other aftermarket equivalents.
- Engine Compatibility: Fits Johnson/Evinrude 18, 20, 25, 28, 30, and 35 HP 2-stroke models.
- Installation Type: Direct OEM replacement.
- Package Includes: 1x Head Gasket and 1x Water Cover Gasket.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Johnson/Evinrude |
765012 |
| Johnson/Evinrude |
327674 |
| Johnson/Evinrude |
324324 |
| Johnson/Evinrude |
329419 |
| Sierra |
18-3899 |
| Sierra |
18-3803 |
| GLM |
34570 |
| GLM |
33700 |
| Mallory |
9-63830 |
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/Evinrude Serial Number Guide.
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Johnson/Evinrude |
Various |
18 |
2-Stroke |
1995-2001 |
765012, 327674 |
|
| Johnson/Evinrude |
Various |
20 |
2-Stroke |
1985-1997 |
765012, 327674 |
|
| Johnson/Evinrude |
Various |
25 |
2-Stroke |
1979-2005 |
765012, 327674 |
|
| Johnson/Evinrude |
Various |
25C |
2-Stroke |
1997-2005 |
765012, 327674 |
Commercial models |
| Johnson/Evinrude |
Various |
28 |
2-Stroke |
1987-1996 |
765012, 327674 |
|
| Johnson/Evinrude |
Various |
30 |
2-Stroke |
1984-2005 |
765012, 327674 |
|
| Johnson/Evinrude |
Various |
35 |
2-Stroke |
1979-1996 |
765012, 327674 |
|
Technical Specifications
| Specification |
Value |
| Product Type |
Gasket Set |
| Installation |
Direct OEM replacement |
| Housing Material |
OEM-spec materials |
| Other Technical Attributes |
Manufactured to OEM specifications |
Package Contents
-
1 x Head Gasket (Replaces: 324324, 329419, 18-3803)
-
1 x Water Cover Gasket (Replaces: 327674, 18-3899, 33700)
Installation Guide
- Disconnect the battery and spark plug wires for safety.
- Drain the engine's cooling system completely.
- Remove the engine cover and any other components obstructing access to the cylinder head and cover.
- Carefully unbolt and remove the cylinder head and water cover. Note the sequence and location of bolts.
- Thoroughly clean all old gasket residue from the engine block and cylinder head mating surfaces.
- Position the new head gasket and water cover gasket onto the clean surfaces.
- Reinstall the cylinder head and water cover. Tighten the bolts to the torque and sequence specified by the manufacturer.
- Reconnect all components, including hoses and spark plug wires.
- Reconnect the battery.
- Refill the cooling system and start the engine, carefully checking for any leaks.
Troubleshooting & FAQ
How do I confirm this gasket set fits my engine?
Check the "Compatible Engine Models" table on this page. Your engine's model, HP, and year should match a line in the table. Cross-referencing your old part number with our "Part Number Cross-Reference" table is also a reliable way to verify fitment.
What are the signs my head gasket is failing?
Common signs include engine overheating, loss of power and compression, milky-white oil, or water/coolant leaking from the engine block and head joint.
How often should head gaskets be replaced?
Head gaskets do not have a fixed replacement interval. They should be replaced whenever the cylinder head is removed for service or if any signs of failure appear.
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.