Yamaha Outboard 6-300hp Gear Case Oil Drain Washer Seals Replaces 90430-08020-0 - 4Boats

Yamaha Outboard Gear Case Oil Drain Washer Seal 90430-08020 6HP-300HP 4Boats

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YAMAHA GEAR CASE SEAL 90430-08020

Name: Yamaha Outboard Gear Case Oil Drain Washer Seal 90430-08020 6HP-300HP 4Boats
Price: 1.99 GBP
Rating: 5.0 (1 reviews)

Premium Quality Lower Unit Replacement Part

Maintaining your outboard's lower unit is critical for long-term reliability. This premium aftermarket gear case oil drain washer is designed to provide a 100% airtight and watertight seal for your Yamaha outboard's drain and fill plugs. Manufactured from high-grade sealing fiber, it acts as a crush-washer to ensure that gear lubricant stays in and corrosive saltwater stays out.

RELIABILITY: Built to meet or exceed OEM 90430-08020-00 specifications for a perfect, leak-free compression every time.

Key Features

✔ Essential for every gear oil change
✔ High-density fiber construction
✔ Direct fit for 8mm drain screws
✔ Prevents catastrophic gear failure

Technical Specs

Inner Diameter:	8mm (5/16")
Outer Diameter:	13mm (approx.)
Thickness:	1.5mm - 1.9mm
Material:	Hard Compression Fiber
Type:	Single-Use Crush Washer

Compatibility / Fitment Guide

Make/System	Model/Application	Notes
Yamaha Outboard	6HP to 300HP (All Models)	2-Stroke & 4-Stroke
Yamaha WaveRunner	Most models 1984 - Current	Includes FX, SJ, XL models
Parsun / Selva	Most Yamaha-based units	Verify against 8mm screw

OEM Cross Reference

Yamaha OEM	90430-08020-00, 90430-08003, 90430-08021, 90430-08801
Yamaha Alternate	604-45342-00-00, 90430-08020-0
Sierra Marine	18-4698

Questions & Answers

Is this a genuine original part?

This is a premium quality aftermarket replacement part from 4Boats, manufactured to meet or exceed original equipment (OE) standards for fitment and performance.

How do I know if it is compatible?

We recommend checking the SKU 90430-08020. This washer fits virtually all Yamaha outboards from 6HP up to 300HP. If your outboard uses an 8mm drain screw, this is the correct seal.

How many washers do I need for a service?

Standard Yamaha lower unit services require two washers: one for the lower drain plug and one for the upper vent/fill plug. We recommend replacing both at every oil change.

Note: Please verify your original part number against the references above before purchasing. This product is sold by 4Boats / Aftermarket.

For the products under £150 the shipping is £6.99.

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Yamaha Outboard Gear Case Oil Drain Washer Seal 90430-08020 6HP-300HP 4Boats