Need help of someone more well versed on Ski doos than myself. Did an engine swap for friend on 01 MXZ 600. Got he sled running, sounds good. Just questioning the coolant is really moving through the fill bottle as soon as the engine is started. Pulled the neck off the top of the engine and checked where I thought the thermostat would be, seem to be a spring loaded valve that moves when I put a screwdriver in to it. Is it normal for coolant to start moving as soon as the engine starts or do I have an issue? TIA