Part Number: 986115
Indmar 986115 Thermostat
Keep your cooling system operating efficiently with the Indmar 986115 Thermostat. Designed as a genuine OEM replacement, this marine thermostat helps regulate coolant flow and maintain proper engine operating temperature for dependable performance on the water.
The thermostat plays a critical role in your engine’s cooling system by controlling when coolant begins circulating through the engine. A worn or sticking thermostat can lead to overheating, inconsistent temperatures, poor fuel efficiency, or extended warm-up times. Replacing a faulty thermostat helps maintain stable engine performance and protects critical internal components from excessive heat.
Built to Indmar factory specifications, the 986115 thermostat is engineered for reliable operation in demanding marine environments. Designed as a direct-fit replacement, it provides proper temperature regulation and dependable cooling system performance under load.
Common Engine Fitments
The Indmar 986115 thermostat is commonly used on GM-based Indmar marine engines, including:
- Indmar Assault 5.7L
- Indmar Monsoon 325
- Indmar Monsoon 340
- Indmar Assault 325
- Indmar 5.0L MPI
- Indmar 5.7L MPI
- Select Indmar 6.0L engine applications
These engines are frequently found in:
- Supra Launch series
- Supra Sunsport models
- Moomba Mobius LSV
- Moomba Outback and Mojo
- Malibu Wakesetter models with Indmar engines
- MasterCraft boats equipped with Indmar power packages
The 986115 thermostat is commonly used in freshwater and closed-cooling engine configurations where maintaining consistent operating temperature is essential for performance and reliability.
Fitment may vary depending on engine serial number and cooling system setup, so confirming compatibility with part number 986115 before ordering is recommended.
Key Features
- Genuine Indmar OEM thermostat
- Maintains proper engine operating temperature
- Helps improve cooling system efficiency and reliability
- Designed for GM-based Indmar marine engines
- Marine-grade construction for dependable performance
- Direct-fit replacement for straightforward installation
Why Replace a Marine Thermostat?
Over time, thermostats can stick open or closed from heat cycles and corrosion. Replacing a worn thermostat helps maintain proper coolant circulation, stabilize engine temperatures, and reduce the risk of overheating-related damage.
If you’re servicing an Indmar-powered wake boat or ski boat, the 986115 thermostat delivers the OEM-quality fit and reliable cooling performance your engine was designed for.