Mercury – Quicksilver 833072003 143°F Thermostat | Mercury 75–115HP OptiMax Outboards | 833072003

Overview

Keeping your outboard at the right temperature means better performance and a longer life. The Quicksilver 833072003 Thermostat is a 143°F OEM replacement designed for Mercury 75–115HP OptiMax outboards (serial 1B227000 and up). It regulates coolant flow so your motor warms up quickly and stays at its ideal operating temperature, no matter the conditions.

Built from corrosion-resistant materials and factory-calibrated for precision, this thermostat ensures your engine runs efficiently, delivers full power, and avoids overheating or running too cool.

Key Features

• Purpose: Maintains the proper 143°F engine temperature for smooth performance and maximum efficiency.
• Material: Made from marine-grade stainless steel and brass, built to handle constant heat and corrosion.
• Performance: Keeps the cooling system working right, preventing overcooling or overheating in demanding marine conditions.
• Design: OEM thermostat tuned specifically for Mercury 75–115HP OptiMax outboards (serial 1B227000 & up).
• Ease of Use / Install: Simple replacement that installs easily with standard tools — no modifications required.

Engine & Boat Compatibility

• Mercury 75HP, 90HP, and 115HP OptiMax outboards (serial 1B227000 and newer)
• Common on bay boats, center consoles, and performance fishing rigs

Performance & Real-World Benefits

The 833072003 thermostat helps your engine reach the correct temperature quickly and maintain it under load. A thermostat that sticks open or closed can cause poor fuel economy, loss of power, or even engine wear. This OEM replacement restores smooth, efficient cooling and steady temperature control.

You’ll get faster warm-ups, consistent running temps, and better overall engine performance — the kind of reliability every boater wants before heading out.

Why Choose OEM

Mercury’s thermostats are built to their exact specs and tested in real marine environments. Aftermarket versions may open at the wrong temperature or corrode prematurely, leading to uneven cooling or engine strain.

A genuine Quicksilver thermostat fits perfectly, responds precisely, and lasts longer — the same quality Mercury installs on every new outboard.

FAQ

Q1: What engines fit this thermostat?
A: It fits Mercury 75–115HP OptiMax outboards, serial 1B227000 and newer.

Q2: What temperature is it rated for?
A: It’s designed to open at 143°F (62°C).

Q3: Is it easy to install?
A: Yes. Remove the old thermostat, drop this one in, and tighten with standard tools.

Q4: How often should it be replaced?
A: Check it annually and replace it every few seasons or if temperature issues appear.

Q5: Why OEM instead of aftermarket?
A: OEM thermostats ensure exact temperature calibration and longer life in salt or freshwater use.