Abstract: A snowmobile coolant system that includes an engine outlet line, an engine inlet line, and an inlet thermostat. The engine outlet line provides coolant flow between an engine and a heat exchanger of the snowmobile. The engine inlet line provides coolant flow between the heat exchanger and the engine. The inlet thermostat is positioned in the engine inlet line and is operable between open and closed states based on a temperature of coolant flowing from the heat exchanger to the inlet thermostat.

Abstract: A flow controller for an engine cooling system is disclosed and claimed. The flow controller includes a housing and a valve. The housing defines a first entrance, a second entrance, and an exit. A main coolant flow path is defined by the first entrance with the exit, and a bypass coolant flow path is defined by the second entrance with the exit. The first entrance is adapted to be connected to the cooler, the second entrance is adapted to be connected to the engine bypass port, and the exit is adapted to be connected to the pump. With the valve closed, the main flow path is blocked; that is, coolant from the cooler and/or reservoir is prevented from entering the pump.