The thermostat is an essential part to a properly functioning water cooling system; wondering where it is on a Honda CX500, GL500, CX650, GL650 etc.? It’s nestled inbetween the cylinder heads – here’s a shot of one on an engine that has been removed from the frame so you can see it more easily:
There’s a coolant tube running to the thermostat housing from each of the cylinder heads, and a rubber hose running to the radiator at the front of the bike. The thermostat bypass hose is visible running back down towards the water pump at the rear of the motor. You can’t see the actual thermostat at this point; you have to open up the thermostat housing and it’s inside there.
Looking for some thermostat sources and available alternatives? See this page!