Thermostat Kit – Fits Johnson/Evinrude 60° V4/V6 Outboards (Replaces 435597)

$29.95

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Product Details

This Thermostat Kit – Fits Johnson/Evinrude 60° V4/V6 Outboards is a direct-fit replacement for Johnson and Evinrude 90–175 HP, 60° V4 & V6 engines manufactured between 1991 and 2006. It ensures your engine maintains the correct operating temperature for optimal performance and longevity.

It serves as a direct interchange for OEM part numbers 435597 / 0435597 and aftermarket equivalents from brands like Sierra (18-3544), GLM (13330), BRP (433395), Eagle Pro (597), and WATERLONG (435597).

Installs as a direct OEM-style replacement.
Features a "Salt Shaker" style thermostat for reliable temperature regulation.
Complete kit includes the thermostat, cover, o-ring, and spring.

Part Number Matrix

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

Brand	Part Number
OMC/Johnson/Evinrude	435597 / 0435597
BRP	433395
Sierra	18-3544
GLM	13330
Eagle Pro	597
WATERLONG	435597

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Johnson/Evinrude owners, this kit is specifically designed for the 60-degree V4 and V6 engine series popular from the early '90s through the mid-2000s.

Brand	Model	Rated HP	Years	OEM Part No.
Johnson/Evinrude	60° V6	150, 175	1991–2006	435597
Johnson/Evinrude	60° V4	90, 115	1995–2006	435597

Technical Specs

Product Type: Thermostat Kit
Installation: Direct OEM Replacement
Thermostat Temperature: 143°F (61.7°C)
Other Technical Attributes: "Salt Shaker" style thermostat
Dimensions: 15.0" L x 10.0" W x 4.0" H
Weight: 0.5 lbs (0.23 kg)

What’s in the Box

1 x Thermostat Cover (338632)
1 x O-Ring (331188)
1 x Spring (337067/338174)
1 x Thermostat (435491)

Installation Notes

Always consult your engine’s service manual for detailed instructions. The general steps are as follows:

Ensure the engine is off and cool. Disconnect the battery.
Locate the thermostat housing(s) on the engine block or cylinder heads.
Use a socket wrench to remove the bolts securing the housing cover.
Carefully lift the cover and remove the old thermostat, spring, and o-ring/gasket.
Clean both mating surfaces of any old gasket material or corrosion.
Place the new thermostat into the housing, ensuring it is oriented correctly. Follow with the new spring.
Install the new o-ring onto the thermostat cover.
Re-attach the cover and tighten the bolts in a crisscross pattern to the manufacturer's specified torque. Do not overtighten.
Reconnect the battery. Run the engine and check for any leaks around the housing.

Troubleshooting & FAQ

How do I know if my engine needs this thermostat kit?

Your engine is listed in the compatibility chart, and you are experiencing symptoms of a faulty thermostat, such as overheating at low speeds or running too cool (failing to reach operating temperature). Visual inspection showing corrosion or a stuck-open/closed thermostat also indicates a need for replacement.

My engine is overheating. Could the thermostat be the problem?

A stuck-closed thermostat is a common cause of overheating. However, overheating can also be caused by a worn water pump impeller, clogged cooling passages, or other issues. A thermostat stuck open will typically cause the engine to run too cool, not overheat.

Why do some V6 outboards require two kits?

Many V6 engines use a separate thermostat for each cylinder bank (port and starboard) to ensure even cooling. If your engine has two thermostat housings, you will need to purchase two kits to service both sides. Always check your service manual to confirm the requirements for your specific model.

What is a "Salt Shaker" style thermostat?

This refers to a type of thermostat that allows a small amount of water to bypass even when closed. This design helps prevent sediment and salt buildup in the cooling passages, which is particularly important for engines operated in saltwater.

Why are there two different part numbers for the spring?

The part numbers (337067 and 338174) may represent supersessions or slight variations from the OEM over the years. The spring included in our kit is a direct replacement for both and will function correctly with the supplied thermostat and cover.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

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 (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

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