Water is important for your outboard motor to function the way it is designed to. Water tends to flow through the cooling system of the motor with the aid of the water pump and then circulates through the powerhead and then exits via the exhaust system. Without it, your outboard motor is going to overheat, which can be caused by a range of different parts of your water cooling system. Here are a few reasons your outboard motor could overheat.
1. Failed water pump
This is by far the most common reason for an outboard motor to overheat. Lack of raw flow of water coupled with the absence of fresh water can result in the water pump failing. Be sure to check for both by taking note of the temperature of your outlet side of the system.
A water flow issue is usually indicated if the temperature is really high. Non-existence of fresh water may be spotted if there’s a huge rise in the temperature between your outlet and the inlet of your heat exchanger.
Further, a water pump may fail due to a faulty heat exchanger. Typically, if there’s no issue with lack of raw water flow or fresh water, it may well be the heat exchanger.
2. The Impeller
This is the device that is used to pressure water below the powerhead, and it’s a pretty common cause of the motor overheating. If you have a corroded impeller, it will does allow your water pump to function optimally. Also, it may shed a few blades, in which case you should trace the water flow to find all the pieces.
If the intake pump goes without water even for a few moments, the rubber impeller may be damaged. But, it’s common for impellers to fail as a result of aging.
To prevent any damage, replace the water impeller every two years.
3. Risers and Manifolds
Exhaust manifolds and risers can clog and then restrict the flow of water through the engine. While this is more common in salt water, it could still cause overheating of outboard motors. Corrosion and rust clog the water passages. This is easy enough to check by touching the risers as the engine is running. If it seems warm to the touch, it is probably clogged. Before you touch it, though, make sure it’s cool enough so you don’t burn your hand!
4. Engine Oil
It is important to check fluids like engine oil on a regular basis. It is often the case that an outboard motor overheats because the oil’s not been changed often enough to allow its pistons to receive the right amount of lubrication. If you do need a new outboard, check out the outboard motors for sale at BBMS Swanwick.
5. The Thermostat
The thermostat is not often the cause of overheating, but it may be damaged due to a high heat. That’s because it plays an important role in keeping your engine at a decent temperature, allowing it to function properly. A damaged of failing thermostat may lead to overheating, and without a functional thermostat, your motor will suffer from poor performance.
Check any of the areas discussed above and be able to find out what is causing your outboard motor to overheat. In case it needs replacement, make sure to purchase only from a reputable retailer.