143° Thermostat Kit – Fits Mercury/Mariner/Force 50-60 HP 3-Cylinder Outboards (Replaces 75692A7)

$82.95 $132.00

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143° Thermostat Kit – Fits Mercury/Mariner/Force 50-60 HP 3-Cylinder Outboards (Replaces 75692A7) is backordered and will ship as soon as it is back in stock.

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Delivery and Shipping

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If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This 143° Thermostat Kit – Fits Mercury/Mariner/Force 50-60 HP 3-Cylinder Outboards (Replaces 75692A7) is engineered for Mercury/Mariner/Force 50-60 HP, 3-cylinder outboard engines from 1988–1990. It is compatible with models made in the USA (S/N 0B110789-0D000749) and Belgium (S/N 9482600-9671686).

This kit provides a direct interchange for Mercury/Mariner part number 75692A7 and GLM 13490.

Designed for direct OEM replacement to ensure proper fit and function.
Maintains optimal engine temperature with a 143° Fahrenheit thermostat.
Includes a complete assembly of the thermostat, gaskets, and essential mounting hardware for a full-service replacement.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury/Mariner	75692A7
GLM	13490

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury, Mariner, and Force models, please verify your engine's serial number falls within the specified ranges for correct fitment.

Brand	Model	Rated HP	Years	OEM Part No.	Notes
Mercury/Mariner/Force	50	50	1988–1990	75692A7	Made in USA, S/N 0B110789-0D000749
Mercury/Mariner/Force	50	50	1988–1990	75692A7	Made in Belgium, S/N 9482600-9671686
Mercury/Mariner/Force	60	60	1988–1990	75692A7	Made in USA, S/N 0B110789-0D000749
Mercury/Mariner/Force	60	60	1988–1990	75692A7	Made in Belgium, S/N 9482600-9671686

Technical Specs

Product Type: Thermostat Kit
Installation: Direct OEM replacement
Thermostat Rating: 143° Fahrenheit
Other Technical Attributes: Complete assembly including thermostat, gaskets, and mounting hardware
Product Dimensions: 33.0" L x 19.8" W x 3.0" H

What’s in the Box

1 x Thermostat (700-13010)
1 x Poppet (700-13801)
1 x Carrier (700-13805)
1 x Grommet (700-13806)
1 x Diaphragm (700-13808)
1 x Washer-Plastic (700-13817)
1 x Spring (700-13822)
1 x Screw #10-16x3/4 (700-21751)
1 x Gasket (700-30610)
1 x Gasket (700-30760)
1 x Gasket (700-30770)
1 x Gasket (700-30800)

Installation Notes

Ensure the engine is off and completely cool. Disconnect the battery for safety.
Drain the engine cooling system to prevent spills.
Locate the thermostat housing on the engine block.
Carefully remove the bolts securing the housing cover. Note the orientation of all parts.
Remove the old thermostat, gaskets, and poppet assembly.
Thoroughly clean the mating surfaces of the housing and cover, removing any old gasket material or corrosion.
Install the new thermostat and gaskets from the kit, ensuring correct alignment.
Re-secure the housing cover, tightening bolts to the manufacturer's recommended torque specifications.
Refill the cooling system with the appropriate coolant.
Reconnect the battery, start the engine, and check for any leaks around the housing. Allow the engine to reach operating temperature to confirm the thermostat opens correctly.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?

Verify that your engine is a Mercury, Mariner, or Force 50 or 60 HP 3-cylinder model made between 1988 and 1990. Most importantly, check that your engine's serial number falls within the specified ranges: USA S/N 0B110789-0D000749 or Belgium S/N 9482600-9671686.

What are the signs of a failing thermostat?

Common symptoms include the engine overheating (stuck-closed thermostat) or failing to reach normal operating temperature (stuck-open thermostat). You might also notice erratic temperature gauge readings or poor engine performance.

How often should a thermostat be replaced?

Thermostats should be inspected and considered for replacement as part of regular cooling system maintenance, typically every few years. It is also wise to replace it when servicing other cooling system components like the water pump.

What happens if the thermostat is stuck open or closed?

A thermostat stuck closed will cause the engine to overheat quickly, which can lead to severe damage. A thermostat stuck open will prevent the engine from warming up properly, leading to increased fuel consumption, higher emissions, and poor performance.

Are all the gaskets in this kit used for one installation?

This kit is designed to cover several similar models. You will only use the specific gaskets that match the configuration of your engine. Compare the new gaskets to your old ones to ensure you select the correct parts for your assembly.

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/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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