64E-43866-09 Yamaha O-Ring | Genuine OEM Yamaha Outboard Part

🔧 Product Description

Genuine Yamaha Outer Tilt Cylinder O-Ring - Part Number: 64E-43866-09

A genuine Yamaha outer sealing O-ring used in selected large-horsepower power trim and tilt cylinder assemblies.

This O-ring seals the outer circumference of the hydraulic cylinder end cap against the cylinder bore. It prevents pressurised trim fluid from leaking past the end cap and blocks water from entering the hydraulic assembly.

⚙️ Key Features

• Genuine Yamaha OEM trim-cylinder O-ring

• Correct current Yamaha part number 64E-43866-09

• Supersedes the earlier 64E-43866-00 reference

• Outer end-cap sealing position

• Cross-references with WSM replacement O-ring 526-57

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 64E-43866-09 → Supersedes 64E-43866-00

• 64E-43866-00 earlier Yamaha trim-cylinder O-ring reference

OEM / Related Numbers:

• 64E-43866-09

• 64E-43866-09-00

• 64E438660900

• 64E-43866-00

• 64E-43866-00-00

• 64E-43867-09 related inner trim-cylinder O-ring

• 64E-43822-00 related dust seal

Aftermarket / Verified Equivalents:

• WSM: 526-57

🚤 Compatibility

Commonly used on:

• Yamaha large-outboard hydraulic trim and tilt cylinders

• Yamaha two-stroke, OX66, HPDI and four-stroke end-cap assemblies

Typically suits:

• Engine models:

• Yamaha 115HP, C115, F115, LF115 and B115

• Yamaha 130HP and L130

• Yamaha 150HP, C150, F150, FL150, L150, LZ150, S150, SX150, V150, VX150, VZ150 and Z150

• Yamaha 175HP, F175, V175, VZ175 and Z175

• Yamaha 200HP, F200, FL200, LF200, L200, LZ200, SX200, V200, VX200, VZ200 and Z200

• Yamaha 225HP, F225, LF225, V225, VX225, VZ225 and Z225

• Yamaha 250HP, F250, LF250, VX250, VZ250 and Z250

• Yamaha VZ300 and Z300 HPDI trim assemblies

• HP Range: 115HP - 300HP

• Engine Type: Yamaha two-stroke, OX66, HPDI and four-stroke outboard

• Year Range: Approximately 1997 - 2018, dependent on trim-cylinder design

🔌 Function

The O-ring seals the trim-cylinder end cap to the hydraulic cylinder body. It allows the hydraulic system to retain operating pressure while protecting the fluid cavity from water and debris.

Common signs of failure:

• Hydraulic fluid visible around the end-cap threads

• Engine trim position slowly drops under load

• Water or corrosion found inside the trim cylinder

• O-ring becomes flattened, cut or swollen

• Trim assembly fails a hydraulic pressure test

📦 Condition

• Genuine Yamaha part

• Brand new

• Supplied in original or equivalent packaging