Thermostat 72°C/162°F – Fits Honda Outboard Motors 20-130 HP
This aftermarket thermostat is engineered to regulate the operating temperature of Honda 4-stroke outboard motors from 20 to 130 HP, covering various models manufactured between 1999 and 2003. It ensures your engine maintains the correct temperature for optimal performance and longevity.
It serves as a direct replacement for multiple Honda and Sierra part numbers, providing a reliable fit for BF20, BF25, BF30, BF40, BF50, BF75, BF90, BF115, and BF130 series engines.
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Operating Temperature: Opens at 72°C / 162°F to control coolant flow.
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Installation: Designed for a direct OEM replacement fit.
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Package Contents: Includes one thermostat.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Honda |
19300-ZV5-043 |
Honda |
19300-ZV5-033 |
Honda |
19300-ZV5-023 |
Honda |
19300-ZV5-013 |
Honda |
19300-ZV5-003 |
Sierra |
18-3630 |
Compatible Engine Models
Confirm your engine model/year in the table below.
Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Honda |
BF20A, BF20A2, BF20A3, BF20AX |
20 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF25A, BF25A1, BF25A2, BF25A3, BF25AW, BF25AX, BF25AY |
25 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF30A, BF30A1, BF30A2, BF30A3, BF30AW, BF30AX, BF30AY |
30 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF35AM |
35 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF40A, BF40A1, BF40A2, BF40A3, BF40AW, BF40AX, BF40AY, BF40B, BF40B2, BF40BX |
40 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF45AM |
45 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF50A, BF50A1, BF50A2, BF50A3, BF50AW, BF50AX, BF50AY |
50 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF75A1, BF75A2, BF75A3, BF75A4, BF75A5, BF75A6, BF75AT, BF75AV, BF75AW, BF75AX, BF75AY |
75 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF90A1, BF90A2, BF90A3, BF90A4, BF90A5, BF90A6, BF90AT, BF90AV, BF90AW, BF90AX, BF90AY |
90 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF115A1, BF115A2, BF115AX, BF115AY |
115 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Honda |
BF130A1, BF130A2, BF130AX, BF130AY |
130 |
4-Stroke |
1999-2003 |
19300-ZV5-043 |
Technical Specifications
Specification |
Value |
Product Type |
Thermostat |
Installation |
Direct OEM replacement |
Operating Temperature |
72°C/162°F (opening temperature) |
Housing Material |
Metal |
Housing Color |
Silver/metallic |
Package Contents
1 x Thermostat (Replaces 19300-ZV5-043)
Important: Gasket (replaces Honda 19351-ZV5-000) is not included and must be purchased separately.
Installation Guide
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Safety First: Ensure the engine is off and cool. Disconnect the negative battery cable.
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Drain Coolant: Place a drain pan under the engine and carefully drain the cooling system.
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Access Housing: Locate and remove the bolts securing the thermostat housing. You may need to gently tap the housing to break the seal.
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Remove Old Parts: Take out the old thermostat and gasket. Note the thermostat's orientation.
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Clean Surfaces: Thoroughly clean both the engine and housing mating surfaces to remove any old gasket material or corrosion.
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Install New Thermostat: Place the new thermostat into the engine block in the correct orientation.
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Install New Gasket: Position the new gasket (sold separately) over the thermostat.
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Reassemble: Reattach the housing and tighten the bolts to the manufacturer's specified torque. Do not overtighten.
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Refill System: Refill the cooling system with the appropriate coolant.
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Final Check: Reconnect the battery, start the engine, and check carefully for any leaks as it comes up to operating temperature.
Troubleshooting & FAQ
Q: How do I confirm this thermostat fits my Honda engine?
A: First, check your engine model and year against our "Compatible Engine Models" table. It is crucial to also verify that your existing thermostat's part number matches one of the numbers in the "Part Number Cross-Reference" list, such as 19300-ZV5-043.
Q: What are the signs of a failing thermostat?
A: Common signs of a bad thermostat include engine overheating, the engine running too cold (not reaching its proper operating temperature), erratic temperature gauge readings, and poor overall engine performance or fuel efficiency.
Q: At what temperature does this thermostat open?
A: This thermostat is designed to begin opening at 72°C (162°F), allowing coolant to circulate through the engine to maintain the correct operating temperature.
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.