Head and Water-Cover Gasket Kit for Johnson/Evinrude Outboards – Replaces 329419 and 327674
Head and Water-Cover Gasket Kit for Johnson/Evinrude Outboards – Replaces 329419 and 327674 is backordered and will ship as soon as it is back in stock.
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Head and Water-Cover Gasket Kit for Johnson/Evinrude Outboards – Re...
Head and Water-Cover Gasket Kit for Johnson/Evinrude Outboards – Replaces 329419 and 327674 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Head and Water-Cover Gasket Kit is intended for selected Johnson/Evinrude outboard applications. The kit combines a head gasket and a water-cover gasket for service involving both sealing locations.
The component references supplied for this kit are Johnson/Evinrude OEM numbers 329419 and 327674. The corresponding Sierra aftermarket references are 18-3803 for the head gasket and 18-3899 for the water-cover gasket.
- Kit format combines the head-gasket and water-cover-gasket components.
- Designed as an aftermarket replacement for the listed OEM references.
- Use the engine model, year, cylinder configuration, and existing gasket numbers to confirm the exact application before ordering.
Part Number Matrix
The numbers below identify the kit components and their documented reference relationships. They should not be treated as a substitute for checking the complete engine model and year.
| Component | Brand | Part Number | Reference |
|---|---|---|---|
| Head gasket | Johnson/Evinrude | 329419 | OEM reference |
| Head gasket | Sierra | 18-3803 | Aftermarket component reference |
| Water-cover gasket | Johnson/Evinrude | 327674 | OEM reference |
| Water-cover gasket | Sierra | 18-3899 | Aftermarket component reference |
| Head gasket | Johnson/Evinrude | 324324, 765012 | Additional replacement references listed for Sierra 18-3803 |
Engine & Model Compatibility
Available catalog information supports the following component-level application details. Because this product is a two-component kit, confirm that both the head-gasket and water-cover-gasket references match your engine.
| Component | Brand | Rated HP | Stroke / Configuration | Years or Application | Reference |
|---|---|---|---|---|---|
| Head gasket | Johnson/Evinrude | 20, 25, 28, 30, 35 HP | 2-cylinder, 2-stroke | 1979–2000 | OEM 329419 / Sierra 18-3803 |
| Water-cover gasket | Johnson/Evinrude | 20, 25, 25C, 30, 35 HP | Outboard application | Confirm by model and year | OEM 327674 / Sierra 18-3899 |
Technical Specs
- Product Type
- Head and water-cover gasket kit
- Product Construction
- Aftermarket replacement gasket components
- Included Component References
- Head gasket: 329419 / 18-3803; water-cover gasket: 327674 / 18-3899
- Application
- Selected Johnson/Evinrude outboard engines; verify both component references before installation
What’s in the Box
- 2 x Head gasket component
- 2 x Water-cover gasket component
The package contents are based on the company kit record, which specifies two of each gasket component. Fasteners, sealants, tools, and other engine parts are not included unless separately stated.
Installation Notes
- Ensure the engine is switched off and completely cool before beginning work. Follow the engine manufacturer’s safety procedures.
- Remove the cowling and any components that obstruct access to the cylinder head and water-cover gasket locations.
- Remove the applicable cover or head assembly and carefully separate the old gasket from the mating surfaces.
- Clean and inspect both mating surfaces. Remove old gasket material without damaging the sealing surfaces.
- Compare each replacement gasket with the removed component and verify that bolt holes and passages align before installation.
- Install the gaskets in their correct locations. Reassemble using the manufacturer’s specified tightening sequence and torque values.
- After reassembly, inspect for water or combustion-gas leaks and confirm normal cooling-system operation before returning the engine to service.
Troubleshooting & FAQ
How do I confirm fitment for my engine?
Check the complete engine model, year, horsepower, cylinder configuration, and the numbers on the gaskets being replaced. The head-gasket reference is associated with 20, 25, 28, 30, and 35 HP two-cylinder applications from 1979–2000, while the water-cover-gasket reference is listed for 20, 25, 25C, 30, and 35 HP applications. Both component applications must match.
Which gasket numbers are included in this kit?
The kit contains head-gasket components corresponding to 329419 and 18-3803, plus water-cover-gasket components corresponding to 327674 and 18-3899. The company kit record specifies two of each component.
Is this an OEM kit?
No. This is an aftermarket replacement kit. Johnson/Evinrude numbers are shown as OEM reference numbers for identification and fitment comparison; the supplied gaskets are aftermarket components.
Can I use only one gasket from the kit?
The kit is sold as a combined head-and-water-cover gasket set. Confirm the required service parts for your engine before installation; unused components should be kept clean and protected from damage.
Should I reuse the old gasket?
No. Gaskets removed during service should generally be replaced, and the manufacturer’s service instructions should be followed for surface preparation, sealant requirements, bolt tightening sequence, and torque.
What are common signs of a failed head or water-cover gasket?
Possible signs include water or combustion-gas leakage, overheating, loss of compression, poor running, or visible leakage around the relevant sealing surface. These symptoms can have multiple causes, so inspect the engine before ordering replacement parts.
Safety & Important Info
- Verify the engine model, year, horsepower, cylinder configuration, and both component references before purchase.
- This is an aftermarket replacement kit, not an OEM component.
- Use the manufacturer’s service manual for torque values, tightening sequence, sealant requirements, and final inspection procedures.
- Professional installation is recommended when cylinder-head or water-cover service is outside your experience.
About Sea Sierra
- Marine Replacement Parts — Replacement components for maintaining and servicing marine engines.
- Application-Focused Listings — Reference numbers and component details are provided to help customers compare parts before ordering.
- Support for Proper Fitment — Match the complete engine information and the individual gasket references before installation.
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