687-44555-00-00 90109-12M21-00 Engine Bolt Assembly | Genuine Used Part

🔧 Product Description

Genuine Yamaha Lower Side Mount Damper and Bolt - Part Numbers: 687-44555-00-00 / 90109-12M21-00

A genuine used Yamaha lower side engine mount with its mounting bolt for selected 40HP to 90HP two-stroke outboards. Part 687-44555-00-00 is the bonded rubber damper; 90109-12M21-00 is the associated mount bolt used on numerous bracket assemblies.

⚙️ Key Features

• Genuine Yamaha lower side mount damper
• Damper part number 687-44555-00-00
• Mounting bolt part number 90109-12M21-00
• Used on 40HP to 90HP two-stroke engines
• Current damper supersedes earlier painted versions

🚤 Compatibility

Commonly used on

• Yamaha 40HP, 50HP, 60HP and 70HP two-stroke outboards
• Yamaha 75HP, 85HP and 90HP two-stroke mounting systems
• Remote-control, tiller and selected Enduro variants

Typically suits

• Confirmed model families include 60F / 70B / 70BETO and 90A / 90TLR
• Catalogue use spans approximately the late 1980s through 2010s
• 90109-12M21 also appears on 40, 50, 60 and 70-series bracket diagrams
• Mount quantity and bolt position vary by engine
• HP Range: Approximately 40HP - 90HP
• Engine Type: Yamaha two-stroke outboard
• Year Range: Approximately late 1980s - 2010s
• Fitment Requirement: Confirm mount position, bolt shoulder and bracket diagram

🔌 Function

The bonded rubber damper supports the lower engine assembly and absorbs vibration and thrust loads; the shoulder bolt locates and clamps the mount.

⚠️ Common Signs of Failure

• Rubber separated from the metal core
• Mount bolt seized or bent
• Excessive engine vibration
• Clunking during acceleration or gear changes
• Corrosion around the mount housing

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 687-44555-00-00 → Supersedes 687-44555-00-94
• 687-44555-00-00 → Supersedes 687-44555-00-4D and 687-44555-A0-94
• 90109-12M21-00 remains a separate Yamaha bolt reference

OEM / Related Numbers

• 687-44555-00-00
• 687-44555-00-94
• 687-44555-00-4D
• 687-44555-A0-94
• 90109-12M21-00
• 688-44511-00-00 related upper mount cover
• 6H3-44552-03-00 related lower mount housing on later engines

Aftermarket / Verified Equivalents

• No verified direct aftermarket bonded mount
• Used genuine Yamaha mounts are the practical replacement
• Equivalent high-tensile mounting bolts must match Yamaha dimensions, shoulder and corrosion protection

📦 Condition

• Genuine used part
• Removed from running engine where applicable
• In good working condition unless otherwise stated