Mercury – Quicksilver Thermostat Kit | 143°F Cooling Component | Mercury, Mariner & OMC Engines | 75692Q03

Overview

Keeping your motor at the right temperature is key to both performance and reliability. The Mercury Marine 75692Q03 Quicksilver Thermostat Kit opens at 143°F, helping your engine warm up quickly and hold steady while running under load. Designed for Mercury and Mariner V6 outboards (135–200 HP) and compatible with select Evinrude and Johnson OMC engines, it’s built from corrosion-resistant materials that hold up in salt or fresh water. It’s a small but vital part that keeps your outboard running smoothly and efficiently, season after season.

Key Features

• Purpose: Controls cooling water flow to maintain ideal engine temperature.
• Temperature Rating: Opens at 143°F for reliable warm-up and steady operation.
• Material: Made from marine-grade metals that resist corrosion and scaling.
• Design: Precision-calibrated for consistent performance and long-term use.
• Performance: Keeps your outboard in its best operating range for cleaner combustion and improved efficiency.
• Ease of Service: Installs easily as a direct-fit replacement with standard tools.

Engine & Boat Compatibility

• Mercury / Mariner V6 135HP, 150HP, 175HP, and 200HP 2-stroke outboards
• Replaces Evinrude and Johnson OMC part #434841
• Also fits:
• 5–55HP 2-cylinder engines
• 85–140HP V4 Crossflow models
• 150–235HP V6 Crossflow models

Performance & Real-World Benefits

The 75692Q03 thermostat helps your engine reach proper operating temperature faster and hold it consistently. Running too cool can waste fuel and cause sluggish performance, while overheating can shorten engine life. This OEM thermostat opens precisely at 143°F, striking the right balance for clean running and strong performance.

Its corrosion-resistant design ensures reliability in marine conditions, and its cross-compatibility makes it an ideal solution for multiple engine types. Swapping out an old thermostat is one of the easiest ways to keep your motor performing like new.

Why Choose Mercury OEM

The Quicksilver 75692Q03 is a genuine Mercury Marine thermostat, made to the same specs used in factory-built engines. Many aftermarket options don’t regulate temperature accurately or break down faster in saltwater.

Mercury’s OEM design is tested for precise temperature response, heat tolerance, and long service life. Choosing OEM ensures your cooling system operates exactly as designed — steady, reliable, and worry-free.

FAQ

Q1: What engines does this thermostat fit?
It fits Mercury and Mariner V6 outboards (135–200 HP) and replaces Evinrude/Johnson OMC #434841.

Q2: What’s its temperature rating?
It opens at 143°F for consistent temperature control.

Q3: Why replace my thermostat?
A worn thermostat can cause overheating, poor fuel economy, or low performance. Replacing it restores proper cooling.

Q4: Is it hard to install?
No — it’s a direct replacement that installs easily with hand tools.

Q5: Why choose OEM?
Mercury OEM thermostats are built for exact fit, corrosion resistance, and lasting reliability in marine use.