Water Jacket Gasket – Fits Johnson/Evinrude 85–140 HP (Replaces 318335, 0318335)
Water Jacket Gasket – Fits Johnson/Evinrude 85–140 HP (Replaces 318335, 0318335) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Jacket Gasket – Fits Johnson/Evinrude 85–140 HP (Replaces 318...
Product Details
This aftermarket Water Jacket Gasket ensures a precise seal for the head cover on Johnson and Evinrude 4-cylinder and V4 2-stroke outboard engines. It is designed for a wide range of models from 85 HP to 140 HP, covering years from 1973 to 1998 and beyond.
It serves as a direct replacement for Johnson/Evinrude part numbers 318335 and 0318335, as well as aftermarket equivalent WSM 505-09.
- Installs on the cylinder head cover to seal water passages.
- Condition: New Old Stock (NOS), without original retail packaging.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 318335 |
| Johnson/Evinrude | 0318335 |
| WSM | 505-09 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | 4 Cyl 3.375 Bore Cross Flow | 85 | 2-Stroke | 1973–1978 | 318335, 0318335 | |
| Johnson/Evinrude | V4 | 85 | 2-Stroke | 1979–1995 | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 88 | 2-Stroke | 1987–Up | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 90 | 2-Stroke | 1981–1994 | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 100 | 2-Stroke | 1979–Up | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 110 | 2-Stroke | 1986–1990 | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 115 | 2-Stroke | 1978–Up | 318335, 0318335 | Head Gasket (also fits 318358) |
| Johnson/Evinrude | V4 | 140 | 2-Stroke | 1978–1984 | 318335, 0318335 | Head Gasket (also fits 318358) |
Technical Specs
- Product Type
- Water Jacket Gasket
- Installation Location
- Head Cover
- Dimensions
- 13.0 x 10.0 x 1.25 in
- Weight
- 0.45 kg (1 lbs)
- Warranty
- 90-Day (Max Marine Outlet), 30-Day (Pine Lake Parts)
- Condition
- New Old Stock (NOS)
What’s in the Box
- 1 x Water Jacket Gasket (Replaces 318335, 0318335)
Installation Notes
- Disconnect the battery and drain the engine's cooling system.
- Remove the engine cowling and any components obstructing access to the cylinder head cover.
- Carefully unbolt and remove the head cover.
- Remove the old water jacket gasket and thoroughly clean all mating surfaces of old gasket material and debris.
- Position the new gasket correctly on the cylinder head.
- Reinstall the head cover and tighten the bolts in the sequence and to the torque specifications recommended by the manufacturer.
- Reassemble all previously removed components.
- Refill the cooling system, reconnect the battery, and run the engine while checking for leaks.
Troubleshooting & FAQ
How do I confirm this gasket fits my engine?
Always verify your engine's HP, model, and year against our compatibility table. Cross-reference the OEM part number (318335 or 0318335) with your service manual or existing part to ensure an exact match.
What are the signs of a failing water jacket gasket?
Common symptoms include external coolant leaks around the cylinder head cover, engine overheating, or water contamination in the engine oil (milky appearance). Prompt replacement is crucial to prevent severe engine damage.
What is the difference between a "Water Jacket Gasket" and a "Cylinder Head Cover Gasket"?
Both terms can describe this part. "Cylinder Head Cover Gasket" is a general term for the seal on the head cover. "Water Jacket Gasket" is more specific, highlighting its primary function of sealing the cooling water passages (the water jacket) within the head assembly.
Do I need to use sealant with this gasket?
Generally, these gaskets are designed to be installed dry. Applying sealant can sometimes interfere with a proper seal unless explicitly required by your engine's service manual. Always clean surfaces thoroughly before installation.
What does "New Old Stock" (NOS) mean?
NOS means the part is genuine and has never been installed but may have been stored for a long time. It may lack original packaging and show minor cosmetic signs of storage, but it is functionally new.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
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 (unused & in original condition). 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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