0436174 0437090 0765585 Thermostat for Johnson Evinrude 90HP 105HP 115HP 135HP 150HP 175HP 200HP 225HP 250HP | JLM Marine

Thermostat for Johnson Evinrude 90HP 105HP 115HP 115HP 135HP 150HP 175HP 200HP 225HP 250HP | JLM Marine

This marine engine thermostat is engineered to fit a wide range of Johnson/Evinrude outboard engines from 90HP to 250HP, covering model years 1995–2006. Designed to regulate engine operating temperature and ensure optimal performance, this thermostat is a critical component for preventing overheating and maintaining efficient cooling system operation.

This thermostat directly replaces OEM part numbers 0436174, 0437090, 0765585, and 0435100, as well as Sierra aftermarket number 18-3545. It provides reliable cross-compatibility for multiple Johnson/Evinrude outboard models across various horsepower ratings.

• Complete kit includes thermostat and thermostat seals for immediate installation
• Fits multiple horsepower ratings from 90HP to 250HP across 1995–2006 model years
• Direct replacement for OEM and aftermarket part numbers

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

This complete thermostat kit includes the following components:

• 1 × Thermostat
• 1 × Thermostat Seals

Installation Guide

1. Safety First: Ensure the engine is completely cool and the ignition is off before beginning work.
2. Locate Thermostat Housing: Identify the thermostat housing on your Johnson/Evinrude outboard engine, typically located on the cylinder head.
3. Remove Cover Bolts: Carefully remove the bolts securing the thermostat housing cover using the appropriate socket or wrench.
4. Extract Old Thermostat: Lift out the old thermostat and remove the old seals or gasket material. Clean all mating surfaces thoroughly with a scraper and solvent.
5. Inspect Surfaces: Check the housing and cover surfaces for cracks, corrosion, or warping that could cause leaks.
6. Install New Seals: Position the new thermostat seals onto the housing or thermostat as per your engine's design.
7. Insert New Thermostat: Place the new thermostat into the housing in the correct orientation (valve side typically faces the engine block).
8. Reinstall Cover: Position the thermostat housing cover and hand-tighten the bolts first to ensure proper alignment.
9. Torque Bolts: Tighten the cover bolts to manufacturer's specifications in a cross-pattern to ensure even pressure and prevent leaks.
10. Refill Coolant: Top off the cooling system with fresh water or the appropriate coolant mixture as specified by your engine manual.
11. Test Operation: Start the engine and monitor for leaks around the thermostat housing. Allow the engine to warm up and verify proper cooling system operation.
12. Final Inspection: After a brief test run, shut down the engine and recheck all bolts and connections for tightness.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my Johnson/Evinrude engine?
A: Cross-reference your engine's model and year with the compatibility table above. You can also verify by checking your current thermostat's OEM part number (0436174, 0437090, 0765585, or 0435100) stamped on the part or listed in your engine manual.

Q: What are the signs that my thermostat needs replacement?
A: Common symptoms include engine overheating, running too cool (poor fuel efficiency), erratic temperature gauge readings, or coolant leaks around the thermostat housing. If your engine's cooling performance has changed, the thermostat should be inspected.

Q: How often should I replace my outboard thermostat?
A: Thermostats should be inspected annually and typically replaced every 2–3 years or sooner if you notice cooling system issues. Saltwater environments may require more frequent replacement due to corrosion and mineral buildup.

Q: Does this kit include the gasket or seals I need?
A: Yes, this complete kit includes both the thermostat and the thermostat seals required for installation, so you have everything needed for a proper repair.

Q: What's the difference between this aftermarket thermostat and the OEM part?
A: 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.

Q: How fast do you ship and how much does it cost?
A: 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.

Q: What is your warranty and return policy?
A: 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.