Thermostat (60°C/140°F) – Fits Suzuki 4-Stroke 70-300 HP Outboards (Replaces 17670-90J00, 17670-90J01)

Thermostat (60°C/140°F) – Fits Suzuki 4-Stroke 70-300 HP Outboards

This thermostat is engineered for a wide range of Suzuki 4-stroke outboard engines from 70 HP to 300 HP (2001–2020) and is also cross-compatible with select Yamaha models. It is a vital component for regulating your engine’s cooling system temperature to ensure optimal performance and prevent overheating.

This part is a direct replacement for Suzuki part numbers 17670-90J00 and 17670-90J01, as well as Sierra 18-3632 and multiple Yamaha part numbers.

• Regulates engine temperature with a 60°C (140°F) opening temperature.
• Designed for direct OEM replacement for easy installation.
• Package includes one thermostat and two thermostat seals.

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. For Suzuki owners, You can review exploded diagrams here to verify part numbers: Suzuki Parts Diagrams & Catalog.

Confirm your engine model/year in the table below. For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Suzuki Models

Yamaha Models (Cross-Compatible)

Technical Specifications

Package Contents

• 1 x Thermostat (Replaces 17670-90J00)
• 2 x Thermostat Seals

Installation Guide

1. Safety First: Ensure the engine is off and cool. Disconnect the negative battery cable.
2. Drain Coolant: Place a drain pan under the engine and carefully drain the coolant to a level below the thermostat housing.
3. Locate Housing: Identify the thermostat housing on the engine block.
4. Remove Housing: Loosen and remove the bolts securing the housing cover. Gently tap the cover if it is stuck, but do not pry it.
5. Remove Old Thermostat: Take out the old thermostat and its gasket or seal. Note the orientation of the thermostat.
6. Clean Surfaces: Thoroughly clean the mating surfaces of the housing and cover, removing all old gasket material and corrosion.
7. Install New Thermostat: Place the new thermostat into the housing in the correct orientation. Install the new seals/gaskets as required.
8. Reassemble: Re-place the housing cover and tighten the bolts to the manufacturer's specified torque.
9. Refill Coolant: Refill the cooling system with the recommended coolant type.
10. Check for Leaks: Reconnect the battery cable, start the engine, and let it warm up. Carefully check for any coolant leaks around the thermostat housing.
11. Final Check: Once the engine reaches operating temperature, check the temperature gauge to ensure it is in the normal range. Top off coolant if necessary after the engine cools down.

Troubleshooting & FAQ

How do I confirm this thermostat fits my engine?
First, check the "Compatible Engine Models" tables on this page to see if your engine's model and year range are listed. Second, cross-reference your existing part number with the numbers in our "Part Number Cross-Reference" table. Using both methods provides the best confirmation.

What are the signs of a failing thermostat?
Common symptoms include the engine overheating, which can cause alarms or steam, or the engine taking an unusually long time to reach its normal operating temperature. An incorrect temperature reading on your gauge can also be an indicator.

Are gaskets or seals included with this thermostat?
Yes, this kit includes one thermostat and two thermostat seals, providing the necessary components for a standard replacement.

What temperature does this thermostat open at?
This thermostat is rated to begin opening at 60°C (140°F) to allow coolant to circulate through the engine.

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.