Thermostat – Fits Honda BF 75-225 HP Outboard Motors (Replaces 19300-ZY3-023, 19300-ZY6-003)

Thermostat – Fits Honda BF 75-225 HP Outboard Motors

This thermostat is designed for Honda Marine 4-Stroke outboard motors, covering models from 75 HP to 225 HP manufactured from 2002 to the present. It precisely maintains the engine's operating temperature, ensuring optimal performance, fuel efficiency, and engine longevity. This is a direct-fit aftermarket replacement, engineered to meet or exceed original equipment specifications.

This component directly replaces Honda OEM part numbers: 19300-ZY3-023 and 19300-ZY6-003.

• Installation Type: Direct Replacement
• Operating Temperature: Calibrated to 50°C (122°F)
• Package Includes: 1 Thermostat, 2 Thermostat Seals

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Thermostat (Replaces 19300-ZY3-023 / 19300-ZY6-003)
• 2 x Thermostat Seals

Installation Guide

1. Ensure the engine is completely cool before starting.
2. Disconnect the negative battery cable to prevent accidental starting.
3. Locate the thermostat housing on the engine. It is typically on the top of the engine block where the main coolant hose connects.
4. Place a drain pan underneath and slowly loosen the housing bolts to allow coolant to drain.
5. Remove the housing, old thermostat, and any existing gasket or seal material.
6. Thoroughly clean both the housing and the engine block mating surfaces to ensure a perfect seal.
7. Install the new thermostat, making sure it is oriented correctly. Place the new seals as required.
8. Reattach the thermostat housing and tighten the bolts to the manufacturer's specified torque. Do not overtighten.
9. Reconnect all hoses and clamps.
10. Refill the cooling system with the manufacturer-recommended coolant.
11. Reconnect the battery cable, start the engine, and let it warm up. Carefully check for any leaks around the housing.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my specific Honda engine?
A: Carefully check your engine model, horsepower, and year against the compatibility table provided on this page. This part is a direct cross-replacement for Honda OEM part numbers 19300-ZY3-023 and 19300-ZY6-003. Verifying these details ensures a correct fit.

Q: What are the symptoms of a failing outboard thermostat?
A: Common signs include the engine overheating, the engine not reaching its proper operating temperature (running too cold), erratic readings on the temperature gauge, or visible coolant leaks near the thermostat housing.

Q: What is the operating temperature of this thermostat?
A: This thermostat is calibrated to begin opening at 50°C (122°F), allowing the engine to warm up quickly and then maintaining a stable temperature for optimal performance.

Q: OEM vs. Aftermarket?
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.