Stainless Steel Outboard Thermostat for Honda BF 8-225 HP Outboard Motors 19300-ZW9-003

Thermostat (60°C) – Fits Honda Marine 8-225 HP Outboard Motors (Replaces 19300-ZW9-003)

This thermostat is designed for a wide range of Honda Marine 4-Stroke outboard engines from 8 to 225 HP (approximated years 1998–present). It ensures your engine maintains the correct operating temperature for optimal performance and longevity. Compatible models include BF8D, BF9.9D, BF15D, BF20D, BF25D, BF30D, BF40A/D, BF50A/D, BF60A, BF75D, BF90D, BF200A, and BF225A.

This unit is a direct replacement for several OEM and aftermarket part numbers, providing a reliable alternative to original components. It is manufactured from a durable stainless steel and copper blend for excellent heat and corrosion resistance.

• Operating Temperature: Opens at 60°C (140°F)
• Installation Type: Direct Fit Engine Mount
• Key Feature: Includes an NBR rubber seal for superior resistance to heat, oil, and corrosion.

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.

Technical Specifications

Package Contents

1 x Thermostat (Replaces 19300-ZW9-003/19300-ZY3-023)

Explosion Diagram

Installation Guide

1. Ensure the engine is completely cool before beginning work.
2. Disconnect the negative battery cable to prevent accidental starts.
3. Locate the thermostat housing on the engine block. It is typically where the top radiator hose connects to the engine.
4. Place a drain pan underneath the housing to catch any spilling coolant.
5. Carefully loosen the hose clamp and detach the coolant hose from the housing.
6. Remove the bolts securing the thermostat housing cover.
7. Take note of the old thermostat's orientation before removing it from the housing.
8. Clean any gasket residue from both the housing and the cover mating surfaces.
9. Install the new thermostat in the same orientation as the original.
10. Re-attach the housing cover with a new gasket (if required) and tighten the bolts to the manufacturer-specified torque.
11. Reconnect the coolant hose and clamp securely.
12. Reconnect the negative battery cable and properly refill the cooling system. Start the engine and check for leaks.

Troubleshooting & FAQ

How do I confirm this thermostat fits my Honda engine?
This thermostat fits a wide range of Honda 4-stroke outboards from 8 HP to 225 HP (1998-Present). The best way to ensure compatibility is to check the "Compatible Engine Models" table on this page. Match your engine model and confirm that your existing part number is 19300-ZW9-003 or 19300-ZY3-023.

What are the signs of a failing thermostat?
Common symptoms include the engine overheating (stuck closed), running too cool and failing to reach proper operating temperature (stuck open), or erratic temperature gauge readings. A faulty thermostat can lead to poor performance, increased fuel consumption, and engine damage.

At what temperature does this thermostat open?
This thermostat is designed to begin opening at 60°C (140°F). This helps the engine warm up quickly and maintains a stable temperature for efficient operation.

Is a gasket included with this part?
The package includes the thermostat only. Depending on your specific model, the gasket may be a separate part. We recommend checking your service manual to see if a new gasket is required for installation.

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.