Thermostat 143°F/62°C for Johnson/Evinrude 3-Cylinder, V4 Loopcharged and V8 Outboards – Replaces 0329766, 0394409, 0434137 and 0765580
Thermostat 143°F/62°C for Johnson/Evinrude 3-Cylinder, V4 Loopcharged and V8 Outboards – Replaces 0329766, 0394409, 0434137 and 0765580 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Thermostat 143°F/62°C for Johnson/Evinrude 3-Cylinder, V4 Loopcharg...
Thermostat 143°F/62°C for Johnson/Evinrude 3-Cylinder, V4 Loopcharged and V8 Outboards – Replaces 0329766, 0394409, 0434137 and 0765580 is backordered and will ship as soon as it is back in stock.
Product Details
This 143°F/62°C thermostat is an aftermarket replacement for selected Johnson and Evinrude outboard cooling systems. It is listed for 3-cylinder engines from 1992 and later, as well as 90° Looper applications from 1990 through 1992. The company fitment listing also covers selected 60, 65, 70, 85, 120, 125, 140, 200, 225, 250 and 300 HP Johnson/Evinrude applications.
The thermostat is supplied as a single replacement component. It is identified as a replacement for Johnson/Evinrude and OMC references 0329766, 0394409, 0434137 and 0765580. The aftermarket reference Sierra 18-3500 is also associated with this thermostat.
- Thermostat for selected Johnson/Evinrude outboard cooling systems.
- Rated purpose: 143°F (62°C).
- Single thermostat replacement, not a multi-part kit.
- Use the engine model, year and OEM reference together when confirming fitment.
Part Number Matrix
These references are provided for identification and cross-reference purposes. Confirm the complete engine application before ordering.
| Brand or Reference | Part Number | Reference Type |
|---|---|---|
| Johnson/Evinrude/OMC | 0329766 | Replacement reference |
| Johnson/Evinrude/OMC | 0394409 | Replacement reference |
| Johnson/Evinrude/OMC | 0434137 | Replacement reference |
| Johnson/Evinrude/OMC | 0765580 | Replacement reference |
| Sierra | 18-3500 | Aftermarket reference |
| GLM | 13170 | Cross-reference |
Engine & Model Compatibility
Compatibility should be confirmed using the engine's brand, horsepower, cylinder configuration, year and required thermostat reference. The available company fitment information identifies the following application groups:
| Brand | Engine Configuration | Horsepower Listed | Year or Application Condition | Related References |
|---|---|---|---|---|
| Johnson/Evinrude | 3-cylinder outboard | 60, 65 or 70 HP | 1992 and later | 0329766, 0394409, 0434137, 0765580 |
| Johnson/Evinrude | 90° Looper | Application-specific | 1990–1992 | 0434137 and related references |
| Johnson/Evinrude | V4 Loopcharged or V8 | 85, 120, 125, 140, 200, 225, 250 or 300 HP | Confirm the exact model and year | 0329766, 0394409, 0434137, 0765580 |
Catalog evidence also documents reference 0434137 on specific 1993 Evinrude 120, 125 and 140 HP 2-stroke models. This supports those applications but does not by itself confirm every engine in the horsepower range.
Technical Specs
- Product Type
- Aftermarket outboard thermostat
- Temperature Rating
- 143°F (62°C)
- Product Format
- Single replacement thermostat
- Application
- Selected Johnson/Evinrude 3-cylinder, V4 Loopcharged, V8 and 90° Looper outboards
- Installation
- Direct replacement when the engine application and reference number match
What's in the Box
- 1 × Thermostat
Gaskets, seals and other installation hardware are not identified as included. Reuse or replace them only as specified by the applicable service manual.
Installation Notes
- Allow the engine to cool completely before beginning work.
- Disconnect the battery according to the service manual and observe all applicable safety precautions.
- Locate the thermostat housing and remove the cover using the procedure for your exact engine.
- Note the original thermostat orientation before removing it.
- Remove the old thermostat and clean the housing mating surfaces without damaging them.
- Install the replacement thermostat in the correct orientation.
- Replace the gasket or seal if required by the service manual; no gasket is identified as included with this product.
- Reinstall the housing cover and tighten the fasteners to the manufacturer's specified torque.
- Restore the cooling system as required for the engine and check for leaks.
- Run the engine according to the service procedure and verify proper cooling-water flow and operating temperature.
Troubleshooting & FAQ
What temperature is this thermostat rated for?
This thermostat is listed with a purpose rating of 143°F (62°C). Use the temperature specification required by your exact engine model and service manual.
Which part numbers does this thermostat replace?
The company listing identifies 0329766, 0394409, 0434137 and 0765580 as replacement references. Sierra 18-3500 and GLM 13170 are also associated cross-references.
Is this a complete thermostat kit?
No. This listing is for one replacement thermostat. A gasket, seal or additional hardware is not identified as included.
Will this fit every Johnson or Evinrude engine from 60 to 300 HP?
No universal fitment should be assumed. The listed horsepower range covers selected 3-cylinder, V4 Loopcharged, V8 and 90° Looper applications. Confirm the exact engine model, year, cylinder configuration and required OEM reference before ordering.
Is this an OEM thermostat?
No. This is an aftermarket replacement component intended to replace the listed OEM and aftermarket references.
How do I confirm compatibility?
Compare your engine's complete model identification and service-manual part number with the compatibility information above. Do not rely on horsepower alone.
Safety & Important Information
- Work only on a cool engine and follow the service manual for your exact model.
- Verify the complete engine model, year, cylinder configuration and reference number before ordering.
- Do not operate the engine if the thermostat housing leaks or the cooling system does not function correctly.
- This is an aftermarket replacement component, not an OEM-branded part.
About Sea Sierra
- Marine Replacement Parts — Practical replacement components for selected outboard and marine applications.
- Application-Focused Listings — Reference numbers and fitment details are provided to help match the correct part.
- Customer Support — Contact support if you need help comparing your engine identification or existing part reference.
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