333008 Air Box Gasket for Johnson Evinrude | JLM Marine

Air Box Gasket for Johnson Evinrude 3 Cyl 50 60 70 HP – OEM 333008

This Air Silencer Tank Cap Gasket is designed for Johnson Evinrude OMC 3-cylinder outboards rated at 50HP, 60HP, and 70HP. It ensures a proper seal for the air box assembly, preventing air leaks and maintaining optimal engine performance.

This aftermarket gasket directly replaces OEM part numbers 333008, 321793, and 777758, as well as aftermarket equivalents from Sierra and GLM Marine.

• Fits Johnson Evinrude OMC 3-cylinder 50–70 HP outboards
• Direct replacement for air silencer tank cap
• Precision-cut for reliable sealing

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/Evinrude Serial Number Guide.

Technical Specifications

Package Contents

This package includes:

• 1× Air Silencer Tank Cap Gasket

Installation Guide

1. Disconnect the battery and ensure the engine is cool before beginning work.
2. Locate the air silencer tank cap on your outboard engine.
3. Remove the cap by unscrewing or unclipping it from the air box assembly.
4. Carefully peel off the old gasket from both the cap and mounting surface. Clean both surfaces thoroughly to remove any residue or debris.
5. Position the new gasket onto the air silencer tank cap, ensuring proper alignment with all mounting holes.
6. Reinstall the cap onto the air box assembly, pressing firmly to seat the gasket evenly.
7. Secure the cap with screws or clips, tightening evenly to manufacturer specifications. Do not overtighten, as this may damage the gasket.
8. Reconnect the battery and start the engine to verify proper sealing and operation.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my Johnson Evinrude engine?
A: Check that your outboard is a 3-cylinder model rated at 50HP, 60HP, or 70HP. Cross-reference your current gasket with OEM part numbers 333008, 321793, or 777758 to ensure compatibility.

Q: What are the signs that my air box gasket needs replacement?
A: Common symptoms include air leaks around the air silencer cap, rough idling, loss of power, or difficulty starting. Visible cracks, brittleness, or deformation of the old gasket also indicate it's time for replacement.

Q: How often should I replace the air box gasket?
A: Replace the gasket whenever you service the air box assembly or notice signs of wear. Regular inspection during annual maintenance is recommended, especially if you operate in harsh marine environments.

Q: Can I reuse the old gasket if it looks intact?
A: No, once a gasket is compressed and conforms to surfaces, reusing it may result in improper sealing. Always install a new gasket during reassembly to ensure a reliable seal.

Q: OEM vs. Aftermarket?
A: 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.

Q: How fast do you ship and how much does it cost?
A: 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.

Q: What is your warranty and return policy?
A: 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.