Name: 4x Yamaha Outboard Gear Case Oil Drain Washer Seals 6-300HP 90430-08020 Gasket
Brand: Yamaha
SKU: 90430-08020a
Price: 3.99 GBP
Availability: InStock

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

4x Yamaha Outboard Gear Case Oil Drain Washer Seals 6-300HP 90430-08020 Gasket

Dispatched in 2-3 days

30 Day Return Policy

In stock, ready to ship
Backordered, shipping soon

Our stock levels are dynamic and can change frequently. If a product appears to be in stock, it may have already sold out. Please contact us if you have any questions about availability. Thank you for your understanding.

£3.99

Tax included.

Yamaha Outboard Gear Case Seals (4-Pack)

Replaces OEM Part: 90430-08020 / 90430-08003

Maintenance of your outboard's lower unit is critical for longevity. These premium gearcase oil drain washers are designed to provide a 100% leak-proof seal for the drain and fill screws on Yamaha outboard engines. Manufactured from high-density specialized fiber material, they compress perfectly to prevent oil leaks and, more importantly, to stop saltwater from entering your gearbox.

RELIABILITY: Engineered to meet or exceed OEM specifications, ensuring a secure seal under high-pressure engine operation.

Key Features

✔ Direct fit for Yamaha Drain/Fill screws
✔ High-density oil-resistant fiber
✔ Essential for every gear oil change
✔ Prevents costly lower unit failure

Technical Specs

Inner Diameter:	8.1mm
Outer Diameter:	12.65mm
Thickness:	1.5mm
Torque Spec:	7 ± 1 Nm

Compatibility / Fitment Guide

Make/System	Model/Application	Years
Yamaha Outboards	2.5 HP to 350 HP (2 & 4-Stroke)	1984 – Present
Mercury Marine	Yamaha-based 4-Stroke Models	All
Selva Marine	All Models utilizing 8mm Drain Plugs	All

OEM Cross Reference

Yamaha OEM: 90430-08020, 90430-08003, 90430-08021, 90430-08801

Sierra Marine: 18-4698, 18-46981-9

Mercury / Mariner: 27-81987, 27-81987M

Mallory Marine: 9-60100

Questions & Answers

Is this a genuine original part?

This is a premium quality aftermarket replacement part, manufactured by 4Boats / Aftermarket 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/MPN and Cross Reference list provided above. If your original part number matches any of these, it is a guaranteed fit for your gearcase screws.

Can I reuse these washers?

No. These are "crush" style fiber gaskets designed for single-use. Once they are compressed during installation, they should be replaced every time the gear oil is changed to ensure a reliable seal.

Note: Please verify your original part number against the references above before purchasing. Distributed by 4boats.co.uk.

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

Free delivery for most items over £150.

Why choose us

QUALITY MARINE PARTS

We source dependable marine products from established suppliers and continually refine our range using customer feedback.

TRUSTED SUPPLIERS

We work with trusted marine suppliers and distribution partners to provide reliable parts, equipment and fulfilment.

Simple_Image_Play_Built_into_Routine_Cosmetics_TikTok_In-Feed_Ad_1080_x_1080_px_10 - 4Boats

PERSONAL SERVICE

Every order is checked by the 4Boats team. Contact us before ordering if you need help with part numbers, compatibility or availability.

4x Yamaha Outboard Gear Case Oil Drain Washer Seals 6-300HP 90430-08020 Gasket