Quicksilver Thermostat Kit for Mercury/Mariner 135-200hp V6 — 2-Pack OEM Quality with Gaskets

Quicksilver 75692Q2 is a direct-fit replacement thermostat kit designed to restore correct cooling temperature for select Mercury and Mariner 135–200hp V6 outboards.

If your Mercury or Mariner V6 outboard is running too hot or fluctuating in temperature, an aging or failed thermostat is often the cause. The Quicksilver 75692Q2 kit contains two OEM-quality thermostats plus gaskets, engineered to match the original specifications so the engine reaches and maintains its optimal operating temperature. This part fits specified serial ranges for 135–150hp, 175hp, and 200hp models—refer to your owner or service manual for exact compatibility and installation steps.

How does this thermostat kit restore proper engine cooling?

Thermostats regulate coolant flow; replacing worn units helps the engine warm up quickly and prevents overheating once at operating temperature. The Quicksilver parts are manufactured to the same tolerances as Mercury original equipment, giving predictable valve opening characteristics and reliable sealing.

• Includes two thermostats for V6 engine banks, ensuring both sides use matched components.
• Two rubber gaskets are provided to secure a leak-free seal at installation points.
• OEM-equivalent fit reduces need for modification or additional parts.

Which outboard models and serial numbers are compatible?

Compatibility depends on engine horsepower and serial-number thresholds. This kit fits 135–150hp V6 models with serial numbers A9046446 and higher, 175hp V6 models with serial numbers C100861 and higher, and 200hp V6 models with serial numbers 6435503 and higher.

• 135–150hp V6: serial No. A9046446 and above.
• 175hp V6: serial No. C100861 and above.
• 200hp V6: serial No. 6435503 and above.

What comes in the kit and what should I prepare for installation?

The Quicksilver 75692Q2 kit includes the two thermostats and matching rubber gaskets required for both cylinder banks on V6 outboards. Before beginning, have your service manual, basic hand tools, and any recommended sealants or coolant replacements on hand.

• Kit contents: two thermostats, two rubber gaskets—one gasket per thermostat.
• Recommended prep: consult the owner/service manual for removal and replacement steps.
• Tip: replace both thermostats at once to maintain even temperature control across the engine.

Will this part improve performance or fuel efficiency?

While not a performance upgrade, a working thermostat helps the engine reach and hold its designed operating temperature, which supports consistent combustion and efficient operation. Restoring correct cooling reduces stress on components and maintains predictable throttle response under load.

• Ensures the engine warms to optimal temperature faster for stable performance.
• Prevents overcooling or overheating that can reduce efficiency or cause damage.
• OEM-grade components preserve manufacturer-intended thermal behavior.

Who is this for: The Quicksilver 75692Q2 replacement thermostat kit is intended for boat owners, mechanics, and service technicians working on Mercury and Mariner V6 outboards within the listed serial ranges who need an OEM-quality replacement. Choose this kit if you want a direct-fit thermostat solution that matches factory specifications, includes the necessary gaskets, and is backed by Quicksilver’s long-standing marine parts reputation. Always cross-check your engine’s serial number and follow the service manual for safe, correct installation.