Re: new owner
Two cooling systems?? Nope , just one system.Water enters near lower unit at intake ports, into water pump (just above lower unit and midsection junction). Water pump is driven by the spinning drive shaft. Water is pumped up a copper tube to the powerhead. Water circulates through cooling passages in powerhead and exits down through lower leg and out thru the prop hub. A thermostat in the power head regulates the temperature of cooling water through the powerhead. Water that spits out the idle relief port (rear-below cowling) is an indication that the pump is working. If you can hold your finger on the motor head for a few seconds, it's not overheating. If this is a new to you motor, you'd be wise to replace the water pump impeller (spinning pump part that pushes/pumps the water). As the impellers age, they can get brittle and come apart. Bits can be pushed up into the power head, clogging up the works. Change the lower unit lube. If the old lube is milky, there's water intrusion into the lower unit (not a good thing). Try running the motor on a boat at the lake or in a barrel of water. Use enough water to cover the water pump (lower unit-mid section junction). Using the muffs is alright, but, you're forcing water past the water pump and isn't a clear indication of the condition of the water pumps efficiency.
Most here will tell you to find a OEM service manual for your motor. All service and maintanance routines are clearly outlined with pictures!
