Thermostat – Fits Johnson/Evinrude 85-135 HP (Replaces 384719, 0384719, 0777838)
This thermostat is designed for Johnson/Evinrude 85-135 HP, 2-Stroke, 1973–1978 cross-flow engines. It ensures your engine maintains the correct operating temperature for optimal performance and longevity.
This component is a direct replacement for Johnson/Evinrude part numbers 384719, 0384719, and 0777838, as well as Sierra 18-3560 and WSM 775-101.
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Installation Method: Direct OEM Replacement
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Operating Temperature: 143°F (62°C)
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Engine Design: Specifically for cross-flow engines
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Johnson/Evinrude |
384719 / 0384719 / 0777838 |
Sierra |
18-3560 |
WSM |
775-101 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.
Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
Johnson/Evinrude |
4 Cyl, 3.375" Bore Cross Flow |
85 |
2-Stroke |
1973-1978 |
384719/0384719 |
|
Johnson/Evinrude |
4 Cyl, 3.500" Bore Cross Flow |
100 |
2-Stroke |
1971-1972 |
384719/0384719 |
|
Johnson/Evinrude |
4 Cyl, 3.500" Bore Cross Flow |
115 |
2-Stroke |
1973-1977 |
384719/0384719 |
|
Johnson/Evinrude |
4 Cyl, 3.500" Bore Cross Flow |
125 |
2-Stroke |
1971-1972 |
384719/0384719 |
|
Johnson/Evinrude |
4 Cyl, 3.500" Bore Cross Flow |
135 |
2-Stroke |
1973-1976 |
384719/0384719 |
|
Technical Specifications
Specification |
Value |
Product Type |
Thermostat |
Installation |
Direct OEM Replacement |
Housing Material |
Brass/Metal Alloy |
Operating Temperature |
143°F (62°C) |
Other Technical Attributes |
For cross-flow engine design |
Package Contents
- 1 x Thermostat (Replaces 384719/0384719)
- Note: Rubber seal/gasket is not included and should be purchased separately.
Installation Guide
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Safety First: Ensure the engine is off and cool. Disconnect the negative battery cable.
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Drain Coolant: Drain the engine block coolant into a suitable container.
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Locate Housing: Find the thermostat housing, typically on top of the cylinder head.
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Remove Cover: Unscrew the bolts holding the thermostat cover in place and carefully remove it.
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Extract Old Thermostat: Note the orientation of the old thermostat before removing it from the housing.
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Clean Surfaces: Thoroughly clean the gasket mating surfaces on both the housing and the cover.
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Install New Thermostat: Place the new thermostat into the housing in the correct orientation.
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Reassemble: Position a new gasket (not included) and reinstall the housing cover, tightening bolts to the manufacturer's torque specification.
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Refill & Check: Refill the cooling system, reconnect the battery, and start the engine. Check for any leaks and monitor the engine temperature.
Troubleshooting & FAQ
How do I confirm this thermostat fits my engine?
First, check the "Compatible Engine Models" table to ensure your specific model and year range are listed. Second, cross-reference your existing part number with those in the "Part Number Cross-Reference" section to confirm a match.
What are common signs of a failing thermostat?
A thermostat can fail by sticking open or closed. If it sticks open, your engine may not reach its proper operating temperature. If it sticks closed, the engine will overheat. Both situations can cause poor performance and potential engine damage.
Does this thermostat include the rubber seal?
No, this thermostat does not come with the required rubber seal or gasket. It must be purchased separately to ensure a proper, leak-free installation.
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.