How do you cool down a boat engine?

The first type, full raw water systems (usually in older boats), pull the water you are in (lake, river, salt) into the engine’s cooling passageways in the engine, removing the heat from the engine by heating the water, and pumping the heated water back in to the lake (or ocean).

How does the cooling system work on an outboard motor?

Outboard motors are typically designed as open loop cooling systems. Meaning the motor draws water from the host body. That water is circulated through the engine, and fuel pump to maintain prop engine temperatures. After passing through the engine or fuel pump the water is then dumped back into the host body.

How do you tell if an outboard motor is overheating?

One of the best ways to tell if your outboard motor is overheating is by checking the dash gauge. You just have to look at the dash gauge for the temperature. If it is green, then you don’t have to worry about anything but if it goes from green to red, then it is an indication that your boat is overheating.

How does a Yamaha outboard cooling system work?

It’s a simple system that works very well. Cooling water is drawn in through the intake grates on your lower unit, up to and through a rubber impeller keyed to the drive shaft on top of the lower unit, and pumped up into the powerhead of your outboard.

Should water coming out of outboard be hot?

Your water flow should appear steady in most outboards. You also want the water coming out to be warm, but not excessively hot.

Why do boats overheat?

The number one cause for overheating boat engines is a problem with the flow of water to the engine. Most boats have a water strainer which catches harmful items before they can cause damage to your engine.

What happens if an outboard motor overheats?

The Danger of an Overheating Engine You can see how that could be much worse if you’re on the lake or even the ocean in boats, instead. An engine that runs too hot can seize up. You risk cracking the engine head itself, warping metal, burning oil, and parts seizing.

What causes an outboard to overheat?

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.

What makes an outboard motor run hot?

Are all outboard motors water cooled?

Outboard motors can efficiently use water for cooling. Water is has greater mass and is a better conductor of heat than air. Automobiles, trucks, and high-tech snowmachines are also water-cooled. The water comes into the outboard’s engine through the lower unit, which is below water level as the boat is moving.

How hot should outboard motor run?

The idle temperature is the important one and it should be in the 150°-160° range. At high speeds the thermostats are bypassed and the pressure relief valve opens so the engine temp will be cooler, usually about 50° above lake water temp.

Why is my outboard peeing hot water?

It’s kinda normal. My experience with Mercurys, Evinrudes is about the same the water is heated as it’s the exchange medium for the engine heat, coolant in your radiator gets a lot hotter. If it’s steaming from your outboard you got an overheating issue, just hot to almost scalding hot , no issue.