90280-04M04 Yamaha Woodruff Key | Genuine OEM Yamaha Outboard Part

🔧 Product Description

Genuine Yamaha 4mm Woodruff Key - Part Number: 90280-04M04

A genuine Yamaha semicircular shaft key used in selected water-pump, flywheel and timing-drive assemblies.

The key locates the driven component on its shaft and transfers rotational force while maintaining accurate angular alignment.

⚙️ Key Features

• Genuine Yamaha OEM woodruff key

• Correct Yamaha part number 90280-04M04

• Precision-machined semicircular profile

• Used in selected mid-range outboard shaft assemblies

• Direct aftermarket replacement keys available

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 90280-04M04 current OEM woodruff-key reference

OEM / Related Numbers:

• 90280-04M04

• 90280-04M04-00

• 4mm Yamaha woodruff key

• Water-pump / flywheel / timing key where specified

Aftermarket / Verified Equivalents:

• Sail Marine: 90280-04M04 replacement key

• Aftermarket Yamaha 4mm woodruff key

🚤 Compatibility

Commonly used on:

• Yamaha water-pump impeller drives

• Selected flywheel and timing-pulley shaft connections

Typically suits:

• Engine models:

• Yamaha 50HP two-stroke

• Yamaha 60HP two-stroke

• Yamaha 70HP two-stroke

• Yamaha 75HP two-stroke

• Yamaha 80HP two-stroke

• Yamaha 85HP two-stroke

• Yamaha 90HP two-stroke

• Yamaha F75 four-stroke

• Yamaha F80A and F80B four-stroke

• Yamaha F90 four-stroke

• Yamaha F100A and F100D four-stroke

• Assemblies whose parts diagram specifies woodruff key 90280-04M04

• HP Range: Approximately 50HP - 100HP

• Engine Type: Yamaha two-stroke and four-stroke outboard

• Year Range: Assembly and shaft controlled.

🔌 Function

The key locks the impeller, flywheel or pulley to the shaft so rotational force is transferred without the component slipping.

Common signs of failure:

• Driven component rotates independently of the shaft

• Key is sheared or distorted

• Keyway is damaged

• Water pump stops turning despite shaft rotation

• Timing or flywheel alignment changes unexpectedly

📦 Condition

• Genuine Yamaha part

• Brand new

• Supplied in original or equivalent packaging