6H3-12411-11 Yamaha Thermostat | Genuine OEM Yamaha Outboard Part

🔧 Product Description

Genuine Yamaha 50°C Two-Stroke Thermostat - Part Number: 6H3-12411-11

A genuine Yamaha cooling-system thermostat for selected 50HP, 60HP and 70HP two-stroke outboards.

The thermostat begins opening at approximately 50°C to regulate engine temperature and cooling-water flow.

⚙️ Key Features

• Genuine Yamaha OEM thermostat
• Correct Yamaha part number 6H3-12411-11
• Nominal opening temperature approximately 50°C / 122°F
• Current replacement for earlier 6H3 thermostat numbers
• Sierra and aftermarket replacements available

🚤 Compatibility

Commonly used on

• Yamaha 50HP to 70HP three-cylinder two-stroke cooling systems

Typically suits

• Engine models:
• Yamaha 50G, 50GEO and 50GETO
• Yamaha 60F, 60FEDO, 60FEHT, 60FEO and 60FETO
• Yamaha 60TDR, 60TLR, 60TR and related models
• Yamaha C60
• Yamaha E60
• Yamaha P60
• Yamaha 70B, 70BEHDO, 70BEMO, 70BEO and 70BETO
• Yamaha 70TDR, 70TLR and 70TR
• HP Range: 50HP - 70HP
• Engine Type: Yamaha carburetted three-cylinder two-stroke outboard
• Year Range: Approximately 1984 - 2009, dependent on engine model

🔌 Function

The thermostat restricts cooling flow while the engine warms and opens as operating temperature reaches its calibrated range.

⚠️ Common Signs of Failure

• Engine overheats because the thermostat remains closed
• Engine runs excessively cold because it remains open
• Temperature fluctuates during operation
• Salt or corrosion prevents thermostat movement
• Poor warm-up, idle quality or fuel economy

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 6H3-12411-11 → Supersedes 6H3-12411-10
• 6H3-12411-10 → Supersedes 6H3-12411-01
• 6H3-12411-01 → Supersedes 6H3-12411-00
• 6H3-12411-00 original Yamaha thermostat reference

OEM / Related Numbers

• 6H3-12411-11
• 6H3-12411-11-00
• 6H3124111100
• 6H3-12411-10
• 6H3-12411-01
• 6H3-12411-00
• 688-12411-10 related thermostat reference
• 6E5-12411-02 related thermostat reference

Aftermarket / Verified Equivalents

• Sierra: 18-3622
• Sierra: 18-3540 related replacement family
• Marine Spare Parts: AM6H3-12411-10
• Sea Sierra: 6H3-12411-11 replacement thermostat
• Generic 50°C thermostat kit: 6H3-12411-11

📦 Condition

• Genuine Yamaha part
• Brand new
• Supplied in original or equivalent packaging