Thermostat – Fits OMC Johnson/Evinrude 55-75 HP (Replaces 396987, 382385)

$20.49 $32.00

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Thermostat – Fits OMC Johnson/Evinrude 55-75 HP (Replaces 396987, 382385) is backordered and will ship as soon as it is back in stock.

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You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This 143°F (62°C) Thermostat – Fits OMC Johnson/Evinrude 55-75 HP (Replaces 396987, 382385) is a direct replacement marine thermostat operating at 143°F (62°C). It is designed for a wide range of OMC Johnson/Evinrude outboard motors from 55 to 75 HP, manufactured between 1968 and 1988, including various 2-stroke models.

It serves as a direct replacement for several part numbers, including OMC 396987, OMC 382385, OMC 778261, Sierra 18-3557, GLM 13080, Volvo Penta 21148403, Chrysler/Force F335068, Mercruiser 47594, and Mallory 9-43024.

Installation: Direct OEM Replacement
Operating Temperature: 143°F (62°C)

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
OMC	396987
OMC	382385
OMC	778261
Sierra	18-3557
GLM	13080
Volvo Penta	21148403
Chrysler/Force	F335068
Mercruiser	47594
Mallory	9-43024

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This thermostat fits a wide range of Johnson and Evinrude 2-stroke outboards from 1968–1988. Check your specific model code against the list below.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Johnson/Evinrude	55872A, 55872R, 55872S, 55873A, 55873R, 55873S, 55972A, 55972C, 55973A, 55973C, 55ES69A, 55ES69C, 55ESL69A, 55ESL69C, TR-10R, TR-10S, TRL-10R, TRL-10S	55	2-Stroke	1968–1969	396987, 382385
Johnson/Evinrude	60072B, 60072D, 60073B, 60073D, 60172C, 60172E, 60173C, 60173E, 60ES70B, 60ES70D, 60ES71C, 60ES71E, 60ESL70B, 60ESL70D, 60ESL71C, 60ESL71E, E60, J60	60	2-Stroke	1970–1971, 1986–1988	396987, 382385
Johnson/Evinrude	65272S, 65273S, 65372R, 65373R, 65ES72S, 65ES73R, 65ESL72S, 65ESL73R, E65, J65	65	2-Stroke	1972–1973, 1984–1986	396987, 382385
Johnson/Evinrude	70442M, 70443M, 70472M, 70473M, 70572B, 70572E, 70573B, 70573E, 70673D, 70773S, 70873C, 70973R, 70EL76D, 70EL77S, 70EL78C, 70EL79R, 70ES74M, 70ES75B, 70ES75E, 70ESL74M, 70ESL75B, 70ESL75E, 70ESLR74M, E70, J70	70	2-Stroke	1974–1985	396987, 382385
Johnson/Evinrude	75542B, 75543B, 75642D, 75643D, 75742S, 75743S, 75842C, 75843C, 75942R, 75943R, 75ELR76D, 75ELR77S, 75ELR78C, 75ELR79R, 75ER76D, 75ER77S, 75ER78C, 75ER79R, 75ESLR75B, 75ESR75B, E75, J75	75	2-Stroke	1975–1988	396987, 382385

Compatibility extends to select Chrysler/Force, Mercruiser, and Volvo Penta engines. Verify your part number before purchase.

Brand	Rated HP	Stroke	OEM Part No.	Notes
Chrysler/Force	70, 90, 105, 120, 135	2-Stroke	F335068
Mercruiser	90, 160, 200	4-Stroke	47594	Fits GM In-line 6 cylinder (4.1-4.8L engines)
Volvo Penta		4-Stroke	21148403	Fits 3.0 GXi, 3.0GXiC sterndrive applications

Technical Specs

Product Type: Marine Thermostat
Installation: Direct OEM Replacement
Operating Temperature: 143°F (62°C)
Housing Color: Silver/Metallic
Warranty: Varies by seller (typically 30 days to 1 year)

What’s in the Box

1 x Thermostat (396987, 382385)

Installation Notes

Allow the engine to cool completely and disconnect the battery.
Locate the thermostat housing. Place a drain pan underneath to catch any coolant.
Remove the housing cover bolts and carefully lift the cover.
Note the orientation of the old thermostat before removing it from the housing.
Thoroughly clean all mating surfaces of old gasket material and corrosion.
Install the new thermostat in the same orientation as the original.
Place the new gasket on the housing and reinstall the cover, tightening bolts to the manufacturer-specified torque in a star pattern.
Reconnect any hoses, refill the cooling system, and check for leaks after starting the engine.

Troubleshooting & FAQ

How do I know if my thermostat is failing?

Common signs include the engine overheating, running too cool and not reaching its proper operating temperature, or large, erratic temperature fluctuations on your gauge.

What is the correct operating temperature for this thermostat?

This thermostat is rated to open at 143°F (62°C) to maintain consistent engine temperature for optimal performance and efficiency.

How often should a marine thermostat be replaced?

It is good practice to inspect your thermostat annually and consider replacing it every 2-3 years as part of routine cooling system maintenance, or immediately if you notice signs of failure.

Does this thermostat come with a gasket?

This package contains the thermostat only. Gaskets are often required for a complete installation and should be purchased separately if not being reused. Please check the "What's in the Box" section for all included components.

Is this an OEM part or an aftermarket one?

This is a high-quality aftermarket replacement part, not an OEM component. It has been engineered to meet or exceed original equipment manufacturer specifications for fit, form, and function and is produced in an ISO 9002 certified facility with strict quality controls.

What are your shipping speed and costs?

We ship worldwide, with most orders arriving in 5–15 days. Standard shipping is free to most locations, with expedited options available at checkout for an additional fee.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. Should an issue arise, contact our support team with your order number. Returns for unused items in their original condition are accepted within our standard return window. Please consult our full policy page or contact us for details.

Safety & Important Info

Verify images and specifications against your original part before purchase. If anything differs—even if your model is listed as compatible—do not order.
This is an aftermarket replacement component, not an original equipment manufacturer (OEM) part.
Professional installation is highly recommended for safety, performance, and to prevent engine damage.

About Sea Sierra

Pro-Grade Standards: We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability.
Fast Global Fulfillment: We offer free standard delivery to most regions, with an average transit time of 5–15 days.
Manufacturer-Direct Value: By removing middlemen, we deliver fair pricing without ever compromising on materials or quality control.

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