Do Yamaha outboards have thermostats?
Yamaha outboard motors are equipped with a thermostat that limits the quantity of cooling water allowed into the motor until the motor reaches its normal operating temperature. The thermostat components are mounted in a cooling passage, under an access cover sealed with a gasket or an O-ring.
How do you test a thermostat on a Yamaha outboard?
Step 1: Remove the thermostat from the motor. NOTE: Some outboards such as Yamaha V MAX models have two thermostats, in which case you would remove them both. Step 2: Put the thermostat in a bowl and immerse it in boiling water. As the thermostat heats up, it should open.
Can I run my outboard without a thermostat?
Yes, you can temporarily run your outboard without the thermostat and not harm the engine. No, you can not remove the thermostat and continue running the engine for long periods of time without causing harm to the engine. Nobody wants to damage their engine and everybody wants to spend more time on the water.
Why is my Yamaha outboard overheating?
The most common cause of outboard motor overheating is water pump failure. Lack of raw water flow and lack of fresh water can cause water pump failure. Check for lack of raw water flow by noting the temperature of the outlet side of the system.
Why do outboard motors have thermostats?
The thermostat prevents the cooling water from getting to the cylinder walls until there is enough heat for efficient combustion. Once the cylinder temperature is up, the thermostat allows the cooling water to flow from the water pump through the water jacket and out the exhaust.
Is it bad to remove thermostat?
TOM: Yes, Lee, removing the thermostat does make the car run cooler. But you should never, ever do it. When the engine is too cool, the thermostat closes and stops the coolant from flowing through the radiator, so the engine heats back up.
What happens if my outboard overheats?
The cooling system keeps the oil temperature down so the oil can lubricate the internal parts of the engine. Overheating ruins the lubrication and the metals parts start melting and sticking together. Or they just break apart with a big bang.