Head and Cover Gasket Set – Fits Johnson/Evinrude 18-35 HP (Replaces 765012, 327674)
Head and Cover 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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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Head and Cover Gasket Set – Fits Johnson/Evinrude 18-35 HP (Replace...
Product Details
This Head and Cover Gasket Set – Fits Johnson/Evinrude 18-35 HP Outboards (Replaces 765012, 327674) is engineered for a precise fit on Johnson/Evinrude 18, 20, 25, 28, 30, and 35 HP, 2-Stroke outboard engines from model years 1979 through 2001.
It provides a direct interchange for Johnson/Evinrude OEM part numbers 765012, 327674, 324324, and 329419, as well as aftermarket equivalents like Sierra 18-3899 and 18-3803.
- Installs as a direct OEM replacement, requiring no modifications.
- Built with premium, OEM-spec materials to ensure a reliable seal and long service life.
- Manufactured in an ISO9002 certified facility to guarantee consistent quality and performance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Johnson/Evinrude | 765012 | OEM Replacement |
| Johnson/Evinrude | 327674 | OEM Replacement |
| Johnson/Evinrude | 324324 | OEM Replacement |
| Johnson/Evinrude | 329419 | OEM Replacement |
| Sierra | 18-3899 | Aftermarket Cross-Reference |
| Sierra | 18-3803 | Aftermarket Cross-Reference |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|
| Johnson/Evinrude | 18 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
| Johnson/Evinrude | 20 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
| Johnson/Evinrude | 25 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
| Johnson/Evinrude | 28 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
| Johnson/Evinrude | 30 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
| Johnson/Evinrude | 35 HP | 2-Stroke | 1979–2001 | 765012, 327674 |
Technical Specs
- Product Type
- Gasket Set
- Installation
- Direct OEM replacement
- Housing Material
- OEM-spec materials
- Other Technical Attributes
- Manufactured to OEM specifications in ISO9002 certified factory
What’s in the Box
- 1 x Head and Cover Gasket Set (Replaces 765012, 327674)
Installation Notes
- Ensure the engine is off and cool to the touch. Disconnect the battery as a safety precaution.
- Remove the engine cowling and any components obstructing access to the cylinder head and cover.
- Carefully unbolt and remove the head/cover. Remove the old gasket and thoroughly clean both mating surfaces of any old gasket material or sealant.
- Place the new gasket into position, ensuring it aligns with all bolt holes and passages.
- Reinstall the head/cover and tighten the bolts in the sequence and to the torque specifications recommended by the manufacturer.
- Reconnect the battery, start the engine, and carefully check for any leaks around the new gasket.
Troubleshooting & FAQ
How do I know if this gasket set will fit my exact engine model?
This set is designed for the specified HP range (18–35 HP) and years (1979–2001) for Johnson/Evinrude 2-stroke outboards. The best way to confirm fitment is to cross-reference your existing part number with those listed in our Part Number Matrix.
What are common signs of a failed head or cover gasket?
Symptoms often include water in the cylinders, a milky appearance in the oil, engine overheating, loss of compression, or visible water/exhaust leaks from the gasket area.
Is this a complete kit for the job?
This package includes the head and cover gasket set as pictured. Depending on the condition of your engine, you may need additional items like new bolts or specific sealants, which are not included.
When should the head gasket be replaced?
Replace the head gasket whenever you notice signs of failure or during a major engine overhaul. There is no fixed service interval; replacement is done on an as-needed basis.
What is the difference between an OEM and an aftermarket gasket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, it is batch-inspected for consistency and quality.
How fast is shipping and what does it cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options 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 issues arise, contact support with your order details. Returns are accepted within our standard window for items that are unused and in original condition. Please see our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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