Motorcycle Repair: 86 Honda shadow VT700c, auto parts store, honda shadow

Question
I believe my thermostat is bad and have removed it. Can the bike be run without one or would that be a bad idea? I cannot purchase a new one at the moment. Thank you.

Answer
Mike, it is not a good idea to leave the thermostat out. The thermostat helps regulate the flow of coolant through the motor. When you take it out, then the flow increases, but it goes too fast to do its job of conducting heat and then dispursing it into the radiator.

You can put the thermostat in a pan of hot water and then increase the heat until the water boils. If it is working you will see it open around 195-210 degrees. If you need a new one, take the old one to an auto parts store and match it to something they have in stock.

If the bike is overheating, be sure that the fan is working properly. Often the fan switch, usually located in the base of the radiator fails and the fan won't come on at all. You can jumper across the leads to see if the fan is working. If it is, but doesn't come on when the engine gets hot, then replace the fan switch. Again, you may be able to match it to a replacement Honda or other car fan switch at any auto parts store.

Bill Silver