Yamaha 90430-08020-00 – Outboard Lower Unit Drain Gasket

The Yamaha 90430-08020-00 Outboard Lower Unit Drain Gasket is a genuine OEM part engineered to provide a secure seal for your outboard’s lower unit drain and fill plugs. This small but critical component prevents gear lube leaks, ensuring that your Yamaha outboard maintains proper lubrication and protection during operation.

Key Features

• OEM Yamaha Part – Designed to meet Yamaha’s exact specifications for fit and performance.
• Prevents Gear Lube Leaks – Maintains a tight seal for drain and fill plugs in the lower unit.
• Universal Fit – Compatible with all Yamaha outboard models.
• Durable Marine-Grade Material – Withstands pressure, heat, and harsh saltwater conditions.
• Essential Maintenance Item – Should be replaced every time the lower unit gear oil is changed.

Compatibility

This gasket is used across all Yamaha outboard engines—from portable 2.5HP models to high-performance offshore V8s.

Always confirm with your owner’s manual or use our compatibility tool to ensure a proper fit before purchase.

Installation Instructions

• Drain the gear lube from your Yamaha outboard by removing the lower unit drain and fill plugs.
• Remove and discard the old gasket(s).
• Place a new Yamaha 90430-08020-00 gasket on both the drain and fill plug.
• Reinstall plugs and torque to Yamaha’s specifications.
• Refill with Yamaha-approved marine gear lube.

Install Time: Less than 10 minutes.

FAQ

 

Do I need to replace the drain gasket at every gear lube change?

Yes. Yamaha recommends replacing these gaskets each time to ensure a leak-free seal.

Can I reuse this gasket?

Reusing old gaskets can cause leaks and gearcase damage. Always replace with new OEM gaskets.

How many gaskets do I need for a gear oil change?

Typically, two gaskets are required—one for the lower drain plug and one for the upper fill plug.

What’s the difference between this gasket and aftermarket versions?

Yamaha OEM gaskets are engineered specifically for Yamaha outboards, ensuring proper sealing and durability under marine conditions. Aftermarket options may not meet the same standards.