Thermostat 60°C – Fits Johnson/Evinrude 90-175 HP (Replaces 0435491, 18-3544, 8M6010305)
Thermostat 60°C – Fits Johnson/Evinrude 90-175 HP (Replaces 0435491, 18-3544, 8M6010305) is backordered and will ship as soon as it is back in stock.
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Thermostat 60°C – Fits Johnson/Evinrude 90-175 HP (Replaces 0435491...
Thermostat 60°C – Fits Johnson/Evinrude 90-175 HP (Replaces 0435491, 18-3544, 8M6010305) is backordered and will ship as soon as it is back in stock.
Product Details
This Thermostat 60°C (140°F) – Fits Johnson/Evinrude 90-175 HP Outboards is a direct-replacement component for Johnson/Evinrude 4 Cylinder and 6 Cylinder 60° and Ficht engines, covering models from 1993 to 2006. It ensures your engine maintains the correct operating temperature for optimal performance and fuel efficiency.
It serves as a direct interchange for Johnson/Evinrude 0435491/765559, Sierra 18-3544, GLM 13130, Quicksilver/Mercury 8M6010305/8M0175329, and Mallory 9-43032/9-43036.
- Designed for direct, hassle-free installation.
- Regulates engine temperature at a 60°C (140°F) rating.
- Manufactured in an ISO 9002 certified facility for quality assurance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 0435491 |
| Johnson/Evinrude | 765559 |
| Sierra | 18-3544 |
| GLM | 13130 |
| Quicksilver/Mercury | 8M6010305 |
| Quicksilver/Mercury | 8M0175329 |
| Mallory | 9-43032 |
| Mallory | 9-43036 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This thermostat is compatible with a range of Johnson/Evinrude outboard engines. Please check your specific model and year against the list to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | 4 Cylinder 3.600 Bore 60° | 90 | 2-Stroke | 1997–2001 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore 60° | 100 | 2-Stroke | 1998–2001 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore 60° | 105 | 2-Stroke | 1997–2001 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore 60° | 115 | 2-Stroke | 1995–2001 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore Ficht | 90 | 2-Stroke | 2001–2002 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore Ficht | 100 | 2-Stroke | 2004–2005 | 0435491 | |
| Johnson/Evinrude | 4 Cylinder 3.600 Bore Ficht | 115 | 2-Stroke | 1998–2006 | 0435491 | |
| Johnson/Evinrude | 6 Cylinder 3.600 Bore 60° Carb | 150 | 2-Stroke | 1993–2006 | 0435491 | |
| Johnson/Evinrude | 6 Cylinder 3.600 Bore 60° Carb | 175 | 2-Stroke | 1993–2006 | 0435491 | |
| Johnson/Evinrude | 6 Cylinder 3.600 Bore Ficht | 150 | 2-Stroke | 1998–1999 | 0435491 | |
| Johnson/Evinrude | 6 Cylinder 3.600 Bore Ficht | 175 | 2-Stroke | 1998–1999 | 0435491 |
Technical Specs
- Product Type
- Thermostat
- Installation
- Direct replacement
- Temperature Rating
- 60°C (140°F)
- Housing Color
- Silver/Metallic
- Operating Temperature
- 60°C (140°F) opening temperature
- Warranty
- 90 Day (aftermarket)
- Other Technical Attributes
- ISO9002 certified manufacturing (JLM Marine)
What’s in the Box
- 1 x Thermostat (0435491)
Installation Notes
- Ensure the engine is completely cool before beginning.
- Disconnect the negative battery cable for safety.
- Place a drain pan under the engine and partially drain the cooling system to a level below the thermostat housing.
- Locate the thermostat housing on the engine block or cylinder head.
- Remove the bolts securing the housing cover. Note their positions if they are different lengths.
- Carefully remove the old thermostat and gasket/seal. Take note of the thermostat's orientation.
- Thoroughly clean the gasket mating surfaces on both the housing and the engine block to remove any old gasket material or corrosion.
- Install the new thermostat in the correct orientation.
- Place the new gasket (sold separately) and reinstall the housing cover.
- Tighten the bolts to the manufacturer's specified torque in a crossing pattern to ensure even pressure.
- Refill the cooling system with the appropriate coolant mix.
- Reconnect the battery cable, start the engine, and let it warm up. Check for any leaks around the housing and ensure the engine reaches its normal operating temperature.
Troubleshooting & FAQ
What temperature does this thermostat open at? I see conflicting information.
This thermostat is rated to open at 60°C (140°F). While some cross-referenced parts may be listed at 143°F (61.7°C), this component is manufactured to the 60°C (140°F) specification, which is the standard for the listed Johnson/Evinrude applications.
How can I tell if my old thermostat is failing?
Common signs of a faulty thermostat include engine overheating (if it's stuck closed) or taking too long to reach operating temperature (if it's stuck open). You may also notice poor engine performance, increased fuel consumption, or alarms from your engine's monitoring system.
Is a gasket included with this thermostat?
This package contains only the thermostat as shown. Gaskets and seals for the housing must be purchased separately. It is critical to use a new gasket during installation to ensure a proper seal and prevent coolant leaks.
How often should I replace my outboard's thermostat?
Thermostats do not have a fixed replacement interval, but it is good preventative maintenance to replace them every 2-3 years, especially if operating in saltwater. They should be inspected whenever the cooling system is serviced.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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