2 pack Mercury 3.0L 200-225-250-300 Thermostat Gasket Cover Rep 27-850318 1 850318

Premium Aftermarket Marine Parts | High Durability | Direct Fit

Product Specification

Description: This is a high-quality aftermarket replacement part designed for harsh marine environments. Engineered to meet OEM standards for performance and durability.

Part Type	Thermostat Cover Gasket
Condition	100% Brand New

Replaces OEM Part Numbers

Please check your original part number before purchase. This part replaces the following numbers:

Brand	Part Number
Mercury Marine	27-850318
Mercury Marine	27-8503181
Mercury Sport Jet	27-8503181
Sierra	18-3675

💡 Tip: The OEM part number is the most accurate way to confirm fitment. If your number matches any above, this part will fit.

Compatibility / Fitment

This part is compatible with the following outboard models:

For: 200-250 Hp 3.0L, (DFI and EFI)

⚠️ Unsure about fitment?
Please message us your engine's Year, Model, and Serial Number. We will check it for you within 24 hours to ensure you get the right part!

Package Includes

You will receive exactly what is shown in the picture:

2 x Thermostat Cover Gasket

Shipping

Orders ship within 2 business day. We use standard shipping with tracking. International shipping available via eBay GSP.

Returns

60-day free return policy. Items must be brand new and uninstalled.

Contact Us

Customer satisfaction is our priority. If you have any issues or fitment questions, please contact us via eBay messages.

On Apr 19, 2026 at 10:03:24 PDT, seller added the following information: