Thermostat Gasket – Fits Mercury Marine 65-125 HP (Replaces 27-430068)

$9.56

Shipping calculated at checkout.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

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 aftermarket Thermostat Gasket – Fits Mercury Marine 65-125 HP (Replaces 27-430068) is designed for a precise fit on Mercury Marine 3-cylinder (65–90 HP) and 4-cylinder (100–125 HP) 2-Stroke outboard engines manufactured between 1999 and 2004.

It serves as a direct replacement for Mercury/Mercruiser part numbers 27-430068, 27-43006-8, 430068, 430067, 430066, 27-430062, 27-430061, and 27-13461A99.

Installs in the engine cooling system.
Used on Mercury Outboard thermostat assemblies.
Engineered to meet or exceed OEM specifications.

Part Number Matrix

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

Brand	Part Number
Mercury/Mercruiser	27-430068
Mercury/Mercruiser	27-43006-8
Mercury/Mercruiser	430068
Mercury/Mercruiser	430067
Mercury/Mercruiser	430066
Mercury/Mercruiser	27-430062
Mercury/Mercruiser	27-430061
Mercury/Mercruiser	27-13461A99
Mercury/Mercruiser	13461A99

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket is compatible with select 2-stroke outboard engines from Mercury Marine.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	65 Jet	65	2-Stroke	1999–2004	27-430068	3-cylinder
Mercury	70	70	2-Stroke	1999–2004	27-430068	3-cylinder, Serial USA 0A996142 & up / Belgium 9483121 & up
Mercury	75	75	2-Stroke	1999–2004	27-430068	3-cylinder, Serial USA 0C222000 & up / Belgium 9589039 & up
Mercury	80 Jet	80	2-Stroke	1999–2004	27-430068	3-cylinder, Serial USA 0A996142 & up / Belgium 9483121 & up
Mercury	90	90	2-Stroke	1999–2004	27-430068	3-cylinder, Serial USA 0A996142 & up / Belgium 9483121 & up
Mercury	100	100	2-Stroke	1999–2004	27-430068	4-cylinder, Serial USA 0B209468 & up / Belgium 9523034 & up
Mercury	115	115	2-Stroke	1999–2004	27-430068	4-cylinder, Serial USA 0C100000 & up / Belgium 9559771 & up
Mercury	125	125	2-Stroke	1999–2004	27-430068	4-cylinder, Serial USA 0D283222 & up / Belgium 9793577 & up

Technical Specs

Product Type: Thermostat Gasket
Installation: Engine Cooling System
Dimensions: 6.0" H x 11.25" W x 0.13" L
Weight: 0.03 lbs (0.014 kg)
Other Technical Attributes: Used on Mercury Outboard thermostat assemblies

What’s in the Box

1 x Thermostat Gasket (27-430068)

Installation Notes

Always disconnect the battery before starting any engine work.
Drain the engine coolant to a level below the thermostat housing.
Locate and carefully unbolt the thermostat housing.
Remove the old thermostat and gasket. Note their orientation.
Thoroughly clean both the housing and engine block mating surfaces. Remove all old gasket material and corrosion.
Place the new gasket (and thermostat) into position. Do not use sealant unless specified by your service manual.
Reinstall the thermostat housing cover and tighten the bolts to the manufacturer's specified torque.
Refill the cooling system with the recommended coolant.
Reconnect the battery, start the engine, and carefully check the housing for any leaks.

Troubleshooting & FAQ

How do I confirm this gasket fits my specific engine?

Review the Engine & Model Compatibility table carefully. This gasket is intended for specific Mercury 65–125 HP 2-Stroke models from 1999–2004. For models with serial number ranges, it is crucial to verify your engine's serial number to ensure a correct fit.

What are the signs of a failing thermostat gasket?

Common symptoms include visible coolant leaks around the thermostat housing, engine overheating alarms, and erratic engine temperature readings on your gauges. A visual inspection may reveal chalky residue or coolant stains near the housing.

Should I use sealant when installing this gasket?

Most modern gaskets of this type are designed for dry installation. Applying sealant can sometimes interfere with a proper seal. Always consult your engine’s official service manual for the most accurate procedure for your model.

How often should I replace my thermostat gasket?

It is best practice to replace the thermostat gasket any time you service the thermostat or the engine's cooling system. This preventative maintenance helps avoid future leaks.

What’s the difference between an OEM part and this aftermarket version?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for consistency and quality.

How fast do you ship and what are the costs?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options will appear at checkout if they are available for your location.

What is your warranty and return policy?

This part is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their 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.

Payment & Security

Payment methods

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.