Thermostat 60°C (140°F) – Fits Johnson/Evinrude 90-175 HP Outboards (Replaces 0435491, 18-3544, 8M6010305)

Thermostat 60°C (140°F) – Fits Johnson/Evinrude 90-175 HP Outboards

This thermostat is a direct replacement for Johnson/Evinrude 4-cylinder (3.600" bore, 60°) and Ficht engines from 90-115 HP (1995–2006). It also fits 6-cylinder (3.600" bore, 60°) and Ficht engines from 150-175 HP (1993–2006).

This part directly replaces Johnson/Evinrude 0435491/765559, Sierra 18-3544, GLM 13130, Quicksilver/Mercury 8M6010305/8M0175329, and Mallory 9-43032/9-43036. It is designed to meet or exceed original equipment specifications.

• Operating Temperature: Opens at 60°C (140°F) to regulate engine temperature.
• Installation: Installs directly into the original housing with no modifications required.
• Quality Standard: Manufactured in an ISO9002 certified facility for consistent quality and performance.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Technical Specifications

Package Contents

1 x Thermostat (0435491)

Installation Guide

1. Ensure the engine is completely cool before starting.
2. Disconnect the battery to prevent accidental starting.
3. Locate the thermostat housing on the engine block. Place a rag underneath to catch any spilled coolant.
4. Carefully remove the bolts securing the thermostat housing cover.
5. Note the orientation of the old thermostat before removing it.
6. Clean the gasket mating surfaces on both the housing and the cover.
7. Install the new thermostat, ensuring it is in the same orientation as the original.
8. Place the new gasket (if included) and reinstall the housing cover.
9. Tighten the cover bolts evenly to the manufacturer's specified torque.
10. Reconnect the battery and check for leaks after starting the engine.

Troubleshooting & FAQ

How do I confirm this thermostat fits my engine?
First, check the "Compatible Engine Models" table to see if your specific model and year range are listed. Next, verify that your existing part number matches one of the numbers in the "Part Number Cross-Reference" table. Using both methods is the most reliable way to ensure a correct fit.

Some websites list this part as 143°F, but yours says 140°F. Is this the right one?
Yes. A slight temperature variance of a few degrees (140°F vs 143°F) is common among different aftermarket and OEM manufacturers for this part number. This component is designed to operate correctly within the specified temperature range for the listed Johnson/Evinrude engines.

What are the signs of a failing thermostat?
Common symptoms include the engine overheating on the gauge, especially at higher RPMs, or the engine failing to reach its normal operating temperature after warming up ("running cold"). Both can negatively impact engine performance and longevity.

OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.