Quicksilver Thermostats & Accessories

Quicksilver Thermostats & Accessories: OEM Precision for Marine Engine Cooling

A marine engine's thermostat is one of those small components that carries enormous responsibility. When it sticks open or closed, the entire cooling system is thrown off balance — causing an engine to run dangerously hot or frustratingly cold, sapping power and accelerating wear. Quicksilver has been engineering solutions to exactly this problem since 1950, and their line of thermostats and accessories reflects decades of OEM-level expertise rooted in Mercury Marine's own engineering labs.

The OEM Advantage in Every Kit

Quicksilver parts are manufactured by Mercury Marine, making them the only marine aftermarket brand built and recommended by an original-equipment manufacturer. Quicksilver parts are manufactured by Mercury Marine, and where there is a choice, they are 100% the same as the equivalent Mercury part except for the labeling or packaging. For a component as precision-sensitive as a thermostat — which must open and close at exact temperature thresholds to protect your engine — that OEM heritage matters enormously.

Replace a sticking or corroded outboard thermostat with a new Quicksilver thermostat and restore the function of an engine that runs too hot or too cold. Most kits include necessary gaskets and associated parts to complete installation. This “everything in one box” approach means DIYers and professional technicians alike can complete a thermostat service without hunting down individual gaskets or O-rings separately.

Broad Engine Coverage Across Top Marine Brands

One of the most compelling aspects of Quicksilver thermostats is the sheer breadth of engine compatibility. Quicksilver offers OEM-quality parts for many of the most popular brands on the water, including Mercury®, Mariner®, Honda®, Yamaha®, Evinrude®/Johnson®, Suzuki® and more. Whether you're servicing a compact 2-stroke 30–60 hp outboard or a high-output V6 135–200 hp powerplant, there is a purpose-built Quicksilver thermostat engineered to match the exact opening temperature and physical dimensions the engine requires.

The lineup extends to MerCruiser sterndrive and inboard engines as well. Quicksilver produces thermostat housing gaskets for select V6 and V8 MerCruiser sterndrives and inboard engines. Kits are available in many temperature ratings for different engine applications , so it's critical to reference your repair manual or engine serial number to confirm the correct specification before ordering.

Why Proper Thermostat Maintenance Matters

Engines can lose power and efficiency if the thermostat is stuck open or closed, resulting in running too cold or too hot. In the marine environment — where saltwater corrosion, extended idle periods, and seasonal layups accelerate component degradation — thermostat failure is more common than many boaters realize. Replacing a worn thermostat proactively, rather than waiting for an overheating alarm, protects the powerhead and prevents far more costly repairs down the line.

As the only marine brand in the aftermarket manufactured and recommended by an original-equipment manufacturer, Quicksilver's engines, lubricants, parts and accessories are engineered, tested and manufactured by experts. That rigorous testing philosophy applies directly to thermostat kits — components that must perform reliably across a wide range of water temperatures, engine loads, and operating conditions.

Shop Quicksilver Thermostats & Accessories

Whether you're performing a routine annual service or diagnosing a cooling system issue, Quicksilver's thermostat kits deliver the fit, function, and confidence of factory-original parts. Explore the full selection of Quicksilver Thermostats & Accessories and find the right kit for your outboard, sterndrive, or inboard engine. For the complete range of Quicksilver marine parts, visit the Quicksilver brand page, or browse all marine thermostats and accessories across top brands.