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Thermostat And Gasket For MerCruiser 3.0L 2.5L 4 6 Cyl 140 120HP 59078T3 18-3650
$63.79
Sale price
$63.79
Regular price
Available to Order
This Thermostat & Gasket is a replacement thermostat and gasket set compatible with MerCruiser 3.0L, 2.5L, 4 and 6 cylinder engines rated at 140HP and 120HP, and matches OEM Part# 59078T3 and 18-3650.
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I needed a forklift part and wasn’t sure which one fit. They asked for the model and serial number, got back to me quickly, and made sure I ordered the right one. Really helpful.
Randy W. — Verified customer
Product Overview
This thermostat and gasket set is designed for MerCruiser marine engines, specifically the 3.0L and 2.5L four and six cylinder models producing 140HP and 120HP. It regulates engine coolant temperature to ensure optimal performance and prevents overheating. This replacement kit is essential for MerCruiser owners maintaining their stern drive or inboard engines.
Key Features & Performance
- Includes thermostat and gasket for a complete cooling system service
- Direct replacement for OEM part numbers 59078T3 and 18-3650
- Constructed from corrosion-resistant materials for marine environments
- Ensures consistent engine operating temperature for fuel efficiency and longevity
- Easy installation with basic hand tools
Fitment & Compatibility
- MerCruiser 3.0L 4-cylinder engines (140HP)
- MerCruiser 2.5L 4-cylinder engines (120HP)
- MerCruiser 4-cylinder and 6-cylinder engines with these displacement and HP ratings
Common Uses
- Replacing old or failed thermostats on MerCruiser outdrive and inboard engines
- Performing routine cooling system maintenance during winterization or spring launch
- Restoring proper engine temperature regulation after overheating episodes
- Ensuring reliable operation in saltwater or freshwater conditions
Technical Specifications
- Part Number(s): 59078T3, 18-3650
Frequently Asked Questions
Q: What temperature does this thermostat open at? A: This thermostat typically opens at the standard marine engine operating temperature, usually around 160°F; verify your engine's specification.
Q: Is the gasket reusable? A: No, the gasket should be replaced each time the thermostat is serviced to ensure a proper seal.
Product appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.