Thermostat, 50°C (122°F) – Fits Suzuki DF40-70/DT9.9-65/PU55 (Replaces 17670-93961, 17670-93962)
Thermostat, 50°C (122°F) – Fits Suzuki DF40-70/DT9.9-65/PU55 (Replaces 17670-93961, 17670-93962) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Thermostat, 50°C (122°F) – Fits Suzuki DF40-70/DT9.9-65/PU55 (Repla...
Product Details
This aftermarket Thermostat, 50°C (122°F) – Fits Suzuki DF40-70/DT9.9-65/PU55 (Replaces 17670-93961, 17670-93962) opens at a precise temperature to regulate cooling system operation in compatible Suzuki outboard engines. It is designed for Suzuki 4-Stroke DF40-70HP (1998–1999) and 2-Stroke DT9.9-65HP engines, including PU55 models, ensuring your engine reaches and maintains optimal operating temperature.
This component serves as a direct cross-reference for Suzuki part numbers 17670-93960, 17670-93961, 17670-93962, 17670-93963, 17670-93964, 17670-94300, 17670-94301, and Johnson/Evinrude (OMC) 5030742.
- Engineered for direct OEM replacement installation.
- Maintains a consistent 50°C (122°F) opening temperature.
- Constructed from corrosion-resistant stainless steel and brass housing.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Suzuki | 17670-93960 |
| Suzuki | 17670-93961 |
| Suzuki | 17670-93962 |
| Suzuki | 17670-93963 |
| Suzuki | 17670-93964 |
| Suzuki | 17670-94300 |
| Suzuki | 17670-94301 |
| Johnson/Evinrude (OMC) | 5030742 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Suzuki Owners: Please verify your engine's model and production year range to ensure this part is the correct fit. Note that years for some 2-Stroke models are not specified and require visual confirmation.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Suzuki | DF40 | 40 | 4-Stroke | 1998–1999 | 17670-93962 |
| Suzuki | DF50 | 50 | 4-Stroke | 1998–1999 | 17670-93962 |
| Suzuki | DF60 | 60 | 4-Stroke | 1998–1999 | 17670-93962 |
| Suzuki | DF70 | 70 | 4-Stroke | 1998–1999 | 17670-93962 |
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Suzuki | DT9.9 | 9.9 | 2-Stroke | 17670-93962 | |
| Suzuki | DT20 | 20 | 2-Stroke | 17670-93962 | |
| Suzuki | DT25 | 25 | 2-Stroke | 17670-93962 | |
| Suzuki | DT30 | 30 | 2-Stroke | 17670-93962 | |
| Suzuki | DT55 | 55 | 2-Stroke | 17670-93962 | |
| Suzuki | DT65 | 65 | 2-Stroke | 17670-93962 | |
| Suzuki | PU55 | 55 | 2-Stroke | 17670-93962 |
Technical Specs
- Product Type
- Marine Outboard Thermostat
- Installation
- Direct OEM Replacement
- Opening Temperature
- 50°C (122°F)
- Housing Material
- Stainless Steel/Brass
- Operating Temperature
- 50°C (122°F) Opening
- Warranty
- Typically 1 Year (Manufacturer-Dependent)
What’s in the Box
- 1 x Thermostat 50°C (17670-93962)
Installation Notes
- Ensure the engine is off and cool. Disconnect the negative battery terminal for safety.
- Place a drain pan under the engine and drain the cooling system as required by your service manual.
- Locate the thermostat housing. It is typically on top of the cylinder head with a coolant hose attached.
- Remove the bolts securing the housing cover. Note their lengths and positions if they differ.
- Carefully remove the cover. If it is stuck, gently tap it with a rubber mallet; do not pry it open.
- Lift out the old thermostat and its gasket or O-ring.
- Thoroughly clean both the housing and cover mating surfaces, removing all old gasket material and corrosion.
- Install the new thermostat in the correct orientation. Install the new gasket or O-ring.
- Reinstall the housing cover and tighten the bolts to the manufacturer's specified torque in a crisscross pattern.
- Refill the cooling system with the recommended coolant, following your service manual's procedure for purging air from the system.
- Reconnect the battery, start the engine, and check for leaks around the housing as the engine warms up.
Troubleshooting & FAQ
How can I tell if my old thermostat is failing?
Common signs of a faulty thermostat include engine overheating (stuck closed) or taking too long to reach operating temperature (stuck open), which can lead to poor performance and increased fuel consumption. An erratic temperature gauge reading can also indicate a problem.
Is this the correct temperature rating for my engine?
This thermostat is rated for 50°C (122°F) as specified for the listed Suzuki models. Using a thermostat with a different temperature rating can cause improper engine operation, leading to carbon buildup, oil dilution, or overheating. Always use the temperature specified by your engine's manufacturer.
What happens if I run the engine without a thermostat?
Running an engine without a thermostat is not recommended. It will prevent the engine from reaching its optimal operating temperature, leading to incomplete fuel combustion, internal carbon deposits, increased engine wear, and poor fuel efficiency.
Is a new gasket required for installation?
Yes, it is critical to use a new thermostat housing gasket or O-ring during installation to ensure a proper seal and prevent coolant leaks. This part does not include the gasket unless specified in the "What's in the Box" section.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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