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

This thermostat opens at 50°C (122°F) to regulate cooling system operation in Suzuki outboard engines. It is engineered for a precise fit and reliable performance, ensuring your engine maintains its optimal temperature.

This part is a direct replacement for multiple OEM numbers and is compatible with Suzuki 4-Stroke DF40, DF50, DF60, and DF70 models (1998-1999) as well as a wide range of 2-Stroke DT series engines (DT9.9, DT20, DT25, DT30, DT55, DT65) and PU55 models.

• Operating Temperature: Opens at 50°C (122°F)
• Installation: Direct replacement for original part
• Compatibility: Replaces Suzuki and Johnson/Evinrude (OMC) part numbers

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.

Suzuki 4-Stroke Engines

Suzuki 2-Stroke Engines

Technical Specifications

Package Contents

• 1 x Thermostat 50°C (17670-93962)

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 drain the cooling system partially, so the level is below the thermostat.
3. Locate Housing: Find the thermostat housing. It's typically on top of the engine where the main coolant hose from the cylinder head connects.
4. Remove Housing: Loosen and remove the bolts securing the thermostat housing cover.
5. Remove Old Part: Carefully remove the old thermostat and the gasket or O-ring. Note the orientation of the thermostat.
6. Clean Surfaces: Thoroughly clean the mating surfaces of the housing and the engine block to ensure a proper seal.
7. Install New Part: Install the new thermostat in the correct orientation, followed by the new gasket.
8. Reassemble: Re-install the housing cover and tighten the bolts to the manufacturer's recommended torque. Do not overtighten.
9. Refill Coolant: Top off the cooling system with the appropriate coolant.
10. Check for Leaks: Reconnect the battery, start the engine, and let it warm up. Carefully check for any leaks around the thermostat housing.

Troubleshooting & FAQ

Q: How do I know if this thermostat fits my Suzuki engine?

A: Start by checking the compatible engine tables on this page. This thermostat is confirmed to fit specific Suzuki DF 4-stroke models from 1998-1999 and a range of DT 2-stroke engines. The most reliable method is to verify your original part number against our cross-reference list, which includes 17670-93962 and other OEM numbers.

Q: What are the common signs of a failing thermostat?

A: Common symptoms include engine overheating if the thermostat is stuck closed, or the engine taking too long to reach its proper operating temperature if it's stuck open. Poor performance, increased fuel consumption, or erratic temperature gauge readings can also indicate a problem.

Q: What temperature does this thermostat operate at?

A: This thermostat is designed to begin opening at 50°C (122°F). This allows coolant to circulate through the engine to maintain the correct operating temperature for optimal performance and efficiency.

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?

• 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.