Thermostat 50°C 804540 853704 Fits MERCURY MARINER 2 2.5 3.5 4 5 6 25 30 HP

Thermostat for Mercury Mariner

This thermostat for Mercury Mariner outboards regulates engine temperature by opening at 50°C, ensuring optimal operating conditions for 2, 2.5, 3.5, 4, 5, 6, 25, and 30 HP models, with OEM cross-reference numbers 804540 and 853704.

Overview

This thermostat is a replacement part for Mercury Mariner outboard engines, maintaining consistent coolant flow. It opens at 50°C to keep the motor within its ideal temperature range. Suitable for small horsepower models from 2 to 30 HP, it ensures reliable performance in various conditions.

Built For Performance

• Opens at 50°C for accurate temperature control
• Constructed from durable materials to resist corrosion
• Direct replacement for Mercury Mariner outboards
• Compatible with 2, 2.5, 3.5, 4, 5, 6, 25, and 30 HP engines
• OEM cross-reference numbers 804540 and 853704
• Ensures proper coolant flow and prevents overheating

Fits These Machines

• for Mercury Mariner 2 HP
• for Mercury Mariner 2.5 HP
• for Mercury Mariner 3.5 HP
• for Mercury Mariner 4 HP
• for Mercury Mariner 5 HP
• for Mercury Mariner 6 HP
• for Mercury Mariner 25 HP
• for Mercury Mariner 30 HP

On-The-Job Use

• Replaces a worn thermostat to maintain proper engine temperature
• Used in small outboard motors for fishing, dinghies, and auxiliary power
• Ensures quick warm-up and consistent cooling in various water conditions
• Ideal for routine maintenance and troubleshooting overheating or overcooling
• Works with both Mercury and Mariner branded engines

Specs At A Glance

Good To Know

Q: What is the opening temperature of this thermostat? A: It opens at 50°C, which is the specified temperature for these Mercury Mariner models.

Q: Does this thermostat come with a gasket? A: It typically does not include a gasket, so reuse the existing one if in good condition or purchase a new gasket separately.

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