Thermostat Kit (143°F/62°C) – Fits Mercury Marine 135-200 HP V6 Outboards (Replaces 75692Q2, 75692T)
Thermostat Kit (143°F/62°C) – Fits Mercury Marine 135-200 HP V6 Outboards (Replaces 75692Q2, 75692T) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Thermostat Kit (143°F/62°C) – Fits Mercury Marine 135-200 HP V6 Out...
Thermostat Kit (143°F/62°C) – Fits Mercury Marine 135-200 HP V6 Outboards (Replaces 75692Q2, 75692T) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Thermostat Kit (143°F/62°C) is engineered to fit a range of Mercury Marine V6 outboards, including 135-150 HP models (S/N A904646 and newer), 175 HP models (S/N C100861 and newer), and 200 HP models (S/N 6435503 and newer).
It serves as a direct cross-reference for multiple OEM and aftermarket part numbers, including Mercury 75692Q2, Sierra 18-3553, and GLM 13340, ensuring a precise fit and function.
- Designed for simple, direct replacement installation in the factory housing.
- Maintains engine temperature at a consistent 143°F (62°C) for optimal fuel efficiency and performance.
- The kit includes two thermostats and four gaskets, providing everything needed for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury | 75692Q2 |
| Mercury | 75692T |
| Mercury | 75692 |
| Sierra | 18-3553 |
| Sierra | 18-3543 |
| GLM | 13340 |
| GLM | 13010 |
| Mallory | 9-60002 |
| Mallory | 9-43019 |
Engine & Model Compatibility
Confirm your engine model and year/serial number in the table below to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | V6 Outboards | 135-150 | 2-Stroke | S/N A904646+ | 75692Q2 | |
| Mercury | V6 Outboards | 175 | 2-Stroke | S/N C100861+ | 75692Q2 | |
| Mercury | V6 Outboards | 200 | 2-Stroke | S/N 6435503+ | 75692Q2 | |
| Mercury | Black Max | 150 | 2-Stroke | 1987+ | 75692Q2 | Confirmed fit |
| Mercury | XR6 | 150 | 2-Stroke | 2001+ | 75692Q2 | Confirmed fit |
Technical Specs
- Product Type
- Thermostat Kit
- Installation
- Direct replacement
- Temperature Rating
- 143°F (62°C)
- Material
- Metal with rubber gasket seals
- Quantity
- Kit of 2 thermostats with 4 gaskets (2 per thermostat)
- Compatibility
- Mercury Marine V6 Outboards
- Application
- Marine outboard cooling system
- Notes
- Will not fit DFI Optimax motors
- Warranty
- Varies by seller (typically 90 days)
What’s in the Box
- 2 x Thermostat (Replaces 75692Q2)
- 4 x Rubber Gasket Seals
Installation Notes
- Disconnect the negative battery cable before starting work.
- Allow the engine to cool completely. Loosen the pressure cap to release any residual pressure.
- Partially drain the engine coolant until the level is below the thermostat housing.
- Remove the bolts securing the thermostat housing cover.
- Carefully remove the old thermostat and gasket. Note the orientation of the thermostat.
- Thoroughly clean all gasket mating surfaces on the housing and cover.
- Install the new thermostat and gasket, ensuring it is seated correctly in the housing.
- Reinstall the cover and tighten the bolts to the manufacturer’s specified torque.
- Refill the cooling system with the appropriate coolant mixture.
- Reconnect the battery, start the engine, and check for any leaks as it warms up to operating temperature.
Troubleshooting & FAQ
How do I confirm this thermostat fits my engine?
Verify your engine's model and serial number against the compatibility table. This kit fits specific Mercury V6 outboards, including 135/150 HP (S/N A904646+), 175 HP (S/N C100861+), and 200 HP (S/N 6435503+). Please note, it will not fit DFI Optimax motors.
What are the signs of a failing thermostat?
Common symptoms include engine overheating, the engine not reaching its proper operating temperature (running too cool), or erratic fluctuations on your temperature gauge. A stuck-open or stuck-closed thermostat can cause these issues.
Do I need to purchase gaskets separately?
No, this is a complete kit. It comes with two thermostats and four new rubber gasket seals, providing all the necessary components for a full replacement on a V6 engine.
What is the recommended replacement schedule for thermostats?
For preventative maintenance, it is advisable to inspect thermostats during annual service and replace them every 2-3 years, or approximately 300 hours of use. This can vary based on operating conditions, especially in saltwater environments.
Is there a difference between this aftermarket kit and the OEM version?
This is an aftermarket replacement part designed to meet or exceed OEM specifications for fit, form, and function. While the OEM kit costs significantly more, our kit provides a reliable, cost-effective solution without compromising on quality materials or performance.
Why does the kit include two thermostats?
The specified Mercury V6 engines use two thermostats as part of their cooling system design. This kit provides both units required for a complete and balanced replacement service.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an original equipment manufacturer (OEM) part.
- Professional installation is highly recommended for safety, proper function, and to prevent engine damage.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability.
- Fast Global Fulfillment — We offer free standard delivery to most regions with an average transit time of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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