I have a 9.9 gamefisher and recently replaced the water pump impeller only to find that the thermostat was clogging the exit and that was what needed replacement. My question is, is the thermostat only there to warm the motor up? Can I run it without it? Water is pumping out really good without it but I am not sure if it is circulating througout the entire motor or if it is just pumping from the lower unit and out the motor? Just wanted to make sure before I ran it. Thanks for the help.