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 (Replaces 19300-ZY3-023, 19300-ZY6-003) is backordered and will ship as soon as it is back in stock.
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Thermostat – Fits Honda BF 75-225 HP Outboard Motors (Replaces 1930...
Thermostat – Fits Honda BF 75-225 HP Outboard Motors (Replaces 19300-ZY3-023, 19300-ZY6-003) is backordered and will ship as soon as it is back in stock.
Product Details
This Thermostat – Fits Honda BF 75-225 HP Outboard Motors is a crucial component designed for Honda Marine 4-Stroke outboard motors, including models from 75 HP to 225 HP manufactured between 2002 and the present. It ensures your engine maintains the correct operating temperature, which is vital for optimal performance, fuel efficiency, and overall longevity.
This part is a direct, multi-fit replacement for Honda OEM part numbers 19300-ZY3-023 and 19300-ZY6-003.
- Installs directly in place of the factory original thermostat.
- Maintains a consistent engine operating temperature of 50°C (122°F).
- Includes two new thermostat seals for a complete installation.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Honda | 19300-ZY3-023 | OEM Reference |
| Honda | 19300-ZY6-003 | OEM Reference |
| Honda | 19300ZY3023 | OEM Reference |
| Honda | 19300ZY6003 | OEM Reference |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
For Honda Marine owners, this thermostat fits a wide range of BF and BFT series 4-stroke engines produced from 2002 onward.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Honda | BF75DK0, DK2, DK3, DK4 | 75 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BF80A, AK1 | 80 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BFT80AK1 | 80 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BF90DK0, DK2, DK4, DK5 | 90 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BF100A, AK1 | 100 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BFT100AK1 | 100 | 4-Stroke | 2002–2012 | 19300-ZY6-003 | |
| Honda | BF115A2, A3, D, DK1 | 115 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF130A2, A3 | 130 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF135A4, AK2 | 135 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF150A4, AK2 | 150 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF175A3, A6, AK1, AK2, AK3 | 175 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF200A2, A3, A6, AK1, AK2, AK3 | 200 | 4-Stroke | 2002–2012 | 19300-ZY3-023 | |
| Honda | BF225A2, A3, A6, AK1, AK2, K3 | 225 | 4-Stroke | 2002–2012 | 19300-ZY3-023 |
Technical Specs
- Product Type
- Thermostat Assy
- Installation
- Direct Replacement
- Operating Temperature
- 50°C (122°F)
- Housing Material
- Stainless Steel, Copper
What’s in the Box
- 1 x Thermostat (19300-ZY3-023/19300-ZY6-003)
- 2 x Thermostat Seals
Installation Notes
- Ensure the engine is completely cool before starting.
- Locate the thermostat housing on the engine block, referring to your service manual if needed.
- Place a drain pan under the housing and slowly loosen the bolts to drain the coolant.
- Remove the old thermostat and gasket or seal. Clean any residue from the housing and cover surfaces.
- Install the new thermostat and seal, ensuring they are oriented correctly.
- Tighten the housing bolts to the manufacturer-specified torque. Do not overtighten.
- Refill the cooling system with the recommended coolant type.
- Start the engine and check for leaks around the housing as it warms up. Top off coolant if necessary.
Troubleshooting & FAQ
How do I know if my thermostat is failing?
Common signs include engine overheating alarms, the engine running too cold (not reaching operating temperature), or visible coolant leaks around the thermostat housing. Poor engine performance or increased fuel consumption can also indicate a problem.
Is this thermostat compatible with both 19300-ZY3-023 and 19300-ZY6-003?
Yes, this thermostat is designed to be a direct interchange for both Honda part numbers. It fits the same range of engine models and operates at the same temperature specification.
How often should I replace my outboard's thermostat?
As a preventative maintenance item, many service manuals recommend replacing the thermostat and water pump impeller every 2-3 years, or more frequently if used in saltwater. Always consult your owner's manual for specific intervals.
What happens if the thermostat is stuck open or closed?
A thermostat stuck open will cause the engine to run too cool, leading to inefficient combustion, carbon buildup, and poor performance. A thermostat stuck closed is more dangerous; it will prevent coolant from circulating, causing the engine to overheat quickly and risking severe damage.
Is this an OEM part or an aftermarket replacement?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. All parts are manufactured in an ISO 9001 certified facility and are batch-inspected for quality and consistency.
How fast is shipping and what does it cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free to most locations, with expedited options available at checkout where applicable.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model is listed as compatible—do not install the part.
- This is an aftermarket replacement component, not an Original Equipment Manufacturer (OEM) part.
- Professional installation is highly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for demanding real-world conditions.
- Fast Global Fulfillment — Enjoy free standard delivery to most regions worldwide, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — By working directly with our manufacturing partners, we offer fair pricing without compromising on materials or quality control.
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