Sierra 118-3543 Marine Thermostat 143° for Johnson/Evinrude Outboards

The Sierra 118-3543 is a high-performance marine thermostat engineered with a temperature rating of 143°F (62°C) for Johnson/Evinrude outboard engines. Sierra products are engineered to meet today's high horsepower engine demands and stand up in the harsh marine environment. This thermostat meets or exceeds the original equipment part it replaces, ensuring reliable performance and proper engine temperature regulation.

Key Features:

• Temperature rating of 143°F (62°C)
• Fits V4 and V6 crossflow engines including 40-250hp E-tech, 6-55hp models, 9.9 4-Stroke (1994-01), and 15 4-Stroke (1994-01)
• Precision-engineered for optimal cooling system performance
• Designed to withstand the harsh marine environment

OEM Cross-References:

This thermostat is interchangeable with Johnson/Evinrude part numbers 378065, 393659, 434841, 437414, 5005440, and 508626. A properly functioning thermostat is essential for maintaining optimal engine operating temperature, which directly affects performance, fuel efficiency, and engine longevity.