Mercury – Quicksilver 825212A1 120°F Thermostat Kit | Mercury & Mariner 30–50HP 4-Stroke Outboards | 825212A1

Overview

Keeping your outboard at the right temperature is essential for smooth performance and engine life. The Quicksilver 825212A1 Thermostat Kit is a 120°F OEM replacement designed for Mercury and Mariner 30–50HP 4-stroke outboards. It keeps your engine running efficiently by maintaining steady cooling system temperature and preventing overheating or cold-running issues.

This two-piece kit includes a precision-calibrated thermostat and a custom-formed gasket. Built to last and easy to replace, it uses a self-cleaning design that flushes away debris, keeping your cooling system working like it should.

Key Features

• Purpose: Maintains the correct 120°F operating temperature for consistent fuel efficiency and engine protection.
• Material: Made from corrosion-resistant stainless steel and brass for long-term durability.
• Performance: Self-cleaning design helps flush debris from the cooling system and ensures precise temperature control.
• Design: Two-piece OEM kit includes a thermostat and custom-formed gasket for a perfect seal and factory fit.
• Ease of Use / Install: Direct replacement that installs easily with common hand tools and no modifications needed.

Engine & Boat Compatibility

• Mercury & Mariner 30HP 4-stroke (1999–2005 USA: 0G760300–1B226999; Belgium: 0P017000–0P400999)
• Mercury & Mariner 40HP 4-stroke (1998–2018 USA: 0G231123 & up; Belgium: 0P017000 & up)
• Mercury & Mariner 50HP 4-stroke (1995–2000 USA: 0G231123–0T178499)

Performance & Real-World Benefits

The 825212A1 thermostat keeps your engine right at its sweet spot — warm enough for efficient combustion, but cool enough to avoid stress and wear. Its self-cleaning design prevents clogging and helps maintain consistent cooling performance over time.

If your engine has been running too cold, overheating, or showing erratic temperature readings, replacing the thermostat with this OEM kit will restore proper operation and peace of mind.

Why Choose OEM

Mercury’s OEM thermostats are precision-calibrated for exact temperature response and built to last in marine conditions. Aftermarket versions can open at the wrong temperature or corrode prematurely, causing performance issues.

A genuine Quicksilver thermostat ensures proper fit, fast warm-up, and reliable temperature control — exactly what your engine was designed for.

FAQ

Q1: What engines fit this thermostat kit?
A: It fits Mercury and Mariner 30–50HP 4-stroke outboards, including U.S. and Belgium-built models (1995–2018).

Q2: What temperature is it rated for?
A: It’s a 120°F thermostat, calibrated for precise cooling performance.

Q3: What’s included in the kit?
A: One thermostat and one custom-formed gasket.

Q4: Is installation difficult?
A: No, it’s a quick swap that can be done with standard tools and your owner’s manual.

Q5: Why OEM instead of aftermarket?
A: OEM thermostats match Mercury’s original specs and are corrosion-tested for long-term reliability.