18-3672 For Johnson Evinrude 5-235Hp Thermostat with Gasket 434841 5005440

Thermostat with Gasket for Johnson Evinrude

This thermostat with gasket is an aftermarket replacement for Johnson Evinrude outboard engines, regulating coolant flow to prevent overheating, with OEM cross-reference numbers 18-3672, 434841, and 5005440.

Overview

This thermostat with gasket is a direct replacement part for Johnson Evinrude outboard motors, ensuring the engine holds the correct operating temperature across the full 5-to-235 horsepower range. It opens and closes to regulate coolant circulation, protecting the powerhead from both overcooling and overheating. The kit includes a matching gasket for a clean, leak-free seal during installation.

Built For Performance

• Precisely calibrated to open at the factory-specified temperature for Johnson Evinrude outboards
• Corrosion-resistant construction for long service life in saltwater and freshwater
• Includes a new gasket to ensure a positive seal
• OEM-compatible dimensions for a straightforward bolt-on installation
• Replaces worn or stuck thermostats to restore cooling system efficiency

On-The-Job Use

• Maintains consistent engine temperature during trolling and low-speed operation
• Prevents overheating under heavy load or high throttle
• Helps the engine reach operating temperature quickly for better combustion
• Supports reliable performance on fishing boats, runabouts, and other small craft

Specs At A Glance

Good To Know

Q: Will this thermostat fit my specific Johnson Evinrude model? A: It is designed for the 5-235 HP range, but always confirm compatibility with your engine's serial number before ordering.

Q: Does the kit include the mounting hardware? A: It includes the thermostat and gasket, but reusing original fasteners is typical unless they are worn.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.