Thermostat (60°C/140°F) – Fits Suzuki Marine 9.9-70HP (Replaces 17670-94402, 17670-94400, 17670-94404)
Thermostat (60°C/140°F) – Fits Suzuki Marine 9.9-70HP (Replaces 17670-94402, 17670-94400, 17670-94404) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Thermostat (60°C/140°F) – Fits Suzuki Marine 9.9-70HP (Replaces 176...
Product Details
This aftermarket Thermostat (60°C/140°F) is designed for Suzuki outboard engines from 9.9 to 70 HP (4-stroke models, 1999–2009) and select 40 HP 2-stroke models (1984–1998). It functions as an OEM-equivalent temperature control component, ensuring your engine operates within its ideal temperature range.
It serves as a direct replacement for Suzuki part numbers 17670-94400, 17670-94401, 17670-94402, 17670-94403, and 17670-94404, as well as Sierra part 18-3530.
- Direct Fit: Installs as a direct OEM-equivalent replacement with no modifications required.
- Precise Control: Regulates engine temperature by opening at a factory-rated 60°C (140°F).
- Critical Component: An essential part of the cooling system for preventing overheating and ensuring engine longevity.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Suzuki | 17670-94400 / 17670-94401 |
| Suzuki | 17670-94402 / 17670-94403 / 17670-94404 |
| Sierra | 18-3530 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
The following table covers known compatible Suzuki models. This part may also fit some Johnson/Evinrude 4-stroke models (9.9-70 HP, 2000–2007), but it is critical to verify the OEM part number on your engine before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Suzuki | DF9.9 | 9.9 | 4-Stroke | 1999–2009 | 17670-94402/94403/94404 |
| Suzuki | DF15 | 15 | 4-Stroke | 1999–2009 | 17670-94402/94403/94404 |
| Suzuki | DF25 | 25 | 4-Stroke | 2000–2007 | 17670-94402/94403/94404 |
| Suzuki | DF30 | 30 | 4-Stroke | 2000–2007 | 17670-94402/94403/94404 |
| Suzuki | DF40 | 40 | 4-Stroke | 1999–2010 | 17670-94402/94403/94404 |
| Suzuki | DF50 | 50 | 4-Stroke | 1999–2010 | 17670-94402/94403/94404 |
| Suzuki | DF60 | 60 | 4-Stroke | 1998–2009 | 17670-94402/94403/94404 |
| Suzuki | DF70 | 70 | 4-Stroke | 1998–2009 | 17670-94402/94403/94404 |
| Suzuki | DT40 | 40 | 2-Stroke | 1984–1998 | 17670-94402/94403/94404 |
Technical Specs
- Product Type
- Marine Outboard Engine Thermostat
- Installation
- Direct OEM Replacement
- Temperature Rating
- 60°C (140°F)
- Opening Temperature
- 60°C (140°F)
- Housing Color
- Silver/Metallic
- Function
- Regulates engine coolant temperature for optimal performance
What’s in the Box
- 1 x Thermostat
Installation Notes
- Ensure the engine is completely cool. Disconnect the negative battery cable for safety.
- Locate the thermostat housing on the engine block. Place a drain pan below to catch any spilled coolant.
- Carefully remove the bolts securing the housing cover. If stuck, gently tap it loose—do not pry the mating surfaces apart.
- Take note of the old thermostat's orientation before removing it.
- Remove the old thermostat and gasket. Thoroughly clean old gasket material from both the housing and cover surfaces.
- Install the new thermostat in the same orientation as the original, followed by a new gasket (not included).
- Reinstall the housing cover and tighten the bolts evenly to the manufacturer-specified torque.
- Reconnect the battery, start the engine, and carefully inspect the housing for leaks.
- Monitor the engine temperature to confirm it reaches its normal operating range.
Troubleshooting & FAQ
How can I tell if my thermostat has failed?
Common signs include engine overheating at low speeds, running too cool at high speeds, erratic temperature gauge readings, and increased fuel consumption.
What is the purpose of the 60°C (140°F) temperature rating?
This is the temperature at which the thermostat begins to open, allowing coolant to circulate through the engine. It is critical for maintaining optimal operating temperature for performance and fuel efficiency.
Is a new gasket required for installation?
Yes, we strongly recommend using a new thermostat housing gasket during installation to ensure a proper seal and prevent coolant leaks. A new gasket is not included with this thermostat.
How do I know if this fits my specific engine model?
The surest way is to cross-reference the OEM part number from your existing thermostat or service manual with our Part Number Matrix. You can also check your engine's model, horsepower, and year against the compatibility table.
What is the difference between an OEM and an aftermarket part?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials, and manufactured in an ISO 9001 certified facility and batch-inspected for quality and consistency.
What are your shipping speeds and costs?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders; expedited options and exact costs are shown at checkout where available.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused parts in their original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an OEM part.
- Professional installation is 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 real-world conditions.
- Fast Global Fulfillment — With partners worldwide, we offer free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Our model ensures fair pricing without compromising on materials or quality control.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
