65L-14984-00 VST Float Chamber Gasket for Mercury Mariner Yamaha | JLM Marine

65L-14984-00 VST Float Chamber Gasket for Mercury Mariner Yamaha | JLM Marine

This VST Float Chamber Gasket (O-Ring) is designed for Mercury, Mariner, and Yamaha outboard engines ranging from 150 HP to 300 HP. It ensures a reliable seal for the VST (Vapor Separator Tank) float chamber, preventing fuel leaks and maintaining optimal fuel system performance.

This aftermarket replacement directly crosses to multiple OEM part numbers, including 65L-14984-00-00, 18-0715, 809086, and 25-809086, providing a cost-effective solution for fuel system maintenance across Mercury, Mariner, and Yamaha platforms.

• Direct replacement for OEM VST float chamber gaskets
• Suitable for 6-cylinder 76-degree V-block Yamaha engines (200–250 HP models)
• Essential component for fuel system integrity and leak prevention

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 Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

This package includes:

• 1 x VST Float Chamber O-Ring Gasket

The package contains all the parts shown in the product images.

Installation Guide

1. Disconnect the battery and relieve fuel system pressure before beginning work. Ensure the work area is well-ventilated and free from ignition sources.
2. Locate the VST (Vapor Separator Tank) assembly on your outboard engine. Remove any covers or components obstructing access.
3. Carefully disconnect fuel lines from the VST float chamber, using a rag to catch any residual fuel.
4. Remove the retaining screws or clamps securing the VST float chamber cover.
5. Lift off the float chamber cover and inspect the old O-ring gasket for damage or wear.
6. Clean the mating surfaces of both the cover and the chamber body thoroughly, removing all old gasket material and debris.
7. Position the new VST O-ring gasket into the designated groove on the float chamber or cover. Ensure it seats evenly without twisting.
8. Reinstall the float chamber cover, aligning it carefully with the chamber body.
9. Tighten the retaining screws or clamps in a cross-pattern to the manufacturer's specified torque to ensure even pressure.
10. Reconnect fuel lines securely, ensuring all connections are tight and properly seated.
11. Reconnect the battery and turn the ignition to the "on" position to prime the fuel system. Check for leaks around the newly installed gasket.
12. Start the engine and allow it to run at idle, inspecting the VST area for any signs of fuel seepage or leaks.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my specific engine?
A: Cross-reference your original part number with the numbers listed in our Part Number Cross-Reference table above. Also verify your engine model and year in the Compatible Engine Models section. If your model is listed and the part number matches, this gasket will fit.

Q: How often should I replace the VST float chamber gasket?
A: Replace the gasket whenever you service the VST assembly, or if you notice fuel odors, leaks, or hard starting issues. As a preventive measure, inspect the gasket annually and replace it every 2-3 years or sooner if it shows signs of hardening, cracking, or fuel degradation.

Q: What are the signs that my VST gasket is failing?
A: Common symptoms include fuel odor around the VST area, visible fuel weeping from the float chamber seam, difficulty starting the engine, rough idle, or fuel pressure inconsistencies. If you experience any of these issues, inspect and replace the gasket as needed.

Q: Can I reuse the old gasket if it looks okay?
A: No, it is not recommended. O-ring gaskets compress and conform to mating surfaces over time, and reusing them can result in improper sealing and fuel leaks. Always install a new gasket when reassembling the VST float chamber.

Q: Is this an OEM part or an aftermarket replacement?
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.