Thermostat (140°F/60°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 (Replaces 0329766, 0394409)
Thermostat (140°F/60°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 (Replaces 0329766, 0394409) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Thermostat (140°F/60°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 ...
Thermostat (140°F/60°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 (Replaces 0329766, 0394409) is backordered and will ship as soon as it is back in stock.
Product Details
This Thermostat (140°F/60°C) – Fits Johnson/Evinrude 60-300 HP V4/V6/V8 is a direct-fit replacement for Johnson and Evinrude outboard engines ranging from 60 to 300 HP. It is specifically designed for 3-cylinder, V4, V6, and V8 models manufactured between 1985 and 1993.
This unit serves as an interchange for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 0329766, 0394409, 0434137, 0765580, Sierra 18-3500, GLM 13170, and WSM 775-105.
- Designed for direct replacement, ensuring a straightforward installation.
- Operates at a rated temperature of 140°F (60°C) to maintain optimal engine performance.
- Constructed with a durable brass housing for corrosion resistance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 0329766 |
| Johnson/Evinrude | 0394409 |
| Johnson/Evinrude | 0434137 |
| Johnson/Evinrude | 0765580 |
| Sierra | 18-3500 |
| GLM | 13170 |
| WSM | 775-105 |
Engine & Model Compatibility
Confirm your engine model and year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | 3 Cyl 3.187 Bore Looper | 60 | 2-Stroke | 1989–1992 | 0329766 | |
| Johnson/Evinrude | 3 Cyl 3.187 Bore Looper | 65 | 2-Stroke | 1987–1992 | 0329766 | |
| Johnson/Evinrude | 3 Cyl 3.187 Bore Looper | 70 | 2-Stroke | 1986–1992 | 0329766 | |
| Johnson/Evinrude | 4 Cyl 3.500 Small Bore Looper | 120 | 2-Stroke | 1985–1987 | 0329766 | |
| Johnson/Evinrude | 4 Cyl 3.500 Small Bore Looper | 140 | 2-Stroke | 1985–1987 | 0329766 | |
| Johnson/Evinrude | 4 Cyl 3.685 Big Bore Looper | 120 | 2-Stroke | 1988–1992 | 0329766 | |
| Johnson/Evinrude | 4 Cyl 3.685 Big Bore Looper | 125 | 2-Stroke | 1989–1992 | 0329766 | |
| Johnson/Evinrude | 4 Cyl 3.685 Big Bore Looper | 140 | 2-Stroke | 1988–1992 | 0329766 | |
| Johnson/Evinrude | 6 Cyl 3.500 Bore Cross Flow | 185 | 2-Stroke | 1989–1992 | 0329766 | |
| Johnson/Evinrude | 6 Cyl 3.500 Small Bore Looper | 200 | 2-Stroke | 1986–1987 | 0329766 | |
| Johnson/Evinrude | 6 Cyl 3.500 Small Bore Looper | 225 | 2-Stroke | 1986–1987 | 0329766 | |
| Johnson/Evinrude | 6 Cyl 3.685 Big Bore Looper | 200 | 2-Stroke | 1988–1992 | 0329766 | |
| Johnson/Evinrude | 6 Cyl 3.685 Big Bore Looper | 225 | 2-Stroke | 1988–1992 | 0329766 | |
| Johnson/Evinrude | 8 Cyl 3.500 Small Bore Looper | 275 | 2-Stroke | 1985–1987 | 0329766 | |
| Johnson/Evinrude | 8 Cyl 3.500 Small Bore Looper | 300 | 2-Stroke | 1985–1987 | 0329766 | |
| Johnson/Evinrude | 8 Cyl 3.685 Big Bore Looper | 250 | 2-Stroke | 1991–1993 | 0329766 | |
| Johnson/Evinrude | 8 Cyl 3.685 Big Bore Looper | 275 | 2-Stroke | 1988 | 0329766 | |
| Johnson/Evinrude | 8 Cyl 3.685 Big Bore Looper | 300 | 2-Stroke | 1988–1993 | 0329766 |
Technical Specs
- Product Type
- Thermostat
- Installation
- Direct replacement
- Temperature Rating
- 140°F (60°C)
- Operating Temperature
- 143°F/62°C (opening)
- Housing Material
- Metal (brass)
- Design
- Designed for V6 and 3-cylinder engines
What’s in the Box
- 1 x Thermostat (Replaces 0329766, 0394409, 0434137, 0765580)
Installation Notes
- Ensure the engine is cool and disconnect the battery negative terminal.
- Place a drain pan under the engine and drain the cooling system as per your service manual.
- Locate the thermostat housing on the engine block or cylinder head.
- Carefully remove the bolts securing the housing cover.
- Remove the old thermostat and gasket, noting the orientation of the thermostat.
- Thoroughly clean the mating surfaces of the housing and its cover to remove all old gasket material.
- Install the new thermostat in the correct orientation, followed by a new gasket if required.
- Reinstall the housing cover and tighten the bolts to the manufacturer's specified torque.
- Refill the cooling system with the recommended coolant.
- Reconnect the battery, start the engine, and carefully check for leaks as it warms up.
Troubleshooting & FAQ
What are the signs of a faulty thermostat?
A faulty thermostat may cause the engine to overheat (if it's stuck closed) or run too cool (if it's stuck open). This can lead to poor performance, increased fuel consumption, engine alarms, or carbon buildup over time.
At what temperature does this thermostat open?
This thermostat is rated to begin opening at approximately 140°F–143°F (60°C–62°C) to regulate the engine's operating temperature for optimal performance and longevity.
Will this fit my 1994 engine? The chart stops at 1993.
The provided compatibility is based on available data, which primarily covers up to 1993. For models outside this range, you must visually compare your old part to our product photos and confirm that your required OEM part number (e.g., 0329766) is listed as a valid cross-reference in your service manual before ordering.
Why does this part replace so many different part numbers?
Manufacturers often update or supersede part numbers over the production life of an engine series. This thermostat is designed as a direct functional equivalent for all listed cross-references, ensuring broad compatibility.
How often should I replace my outboard's thermostat?
As a key preventative maintenance item, it is good practice to inspect your thermostat annually and replace it every 2-3 years or 200-300 operating hours, particularly if the engine is used in saltwater.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, it is batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
This product is 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 for unused items in original condition. See our 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 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 quality control.
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