# 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

  

🔄 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

  

🚤 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

  

📦 Condition

  

• Genuine Yamaha part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 65.25 AUD
- **Vendor:** Yamaha
- **Tags:** Yamaha Marine Parts | Outboard Engine Parts & Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 65.25 AUD | In stock |

## Images

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

---

> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/6h3-12411-11-thermostat)
> Updated: 2026-07-11