Motorcycle Maintenance Bike Coolant Radiator Motorcycle Repair
Internal combustion engines, by their very nature of operation, create great amounts of heat. In motorcycles this large amount of heat has been addressed (most of the time) by one of two ways. They are either air cooled or water cooled.
If it is air cooled, the wind blowing over the cooling fins will take the heat off the engine. Many people prefer water cooled because sitting at an idle, the heat is not taken away from the bike's engine.
When a motorcycle is water cooled (or you can use a coolant mixture), you don't have to actually be moving for the cooling system to work. The basic principle is exactly the same as it is in a car. It is just on a much smaller scale. When the engine is running, it will circulate the liquid that you have chosen to cool the engine.
Now the problem with this is if the level of the coolant gets low, your bike can overheat. Having your bike overheat can range from simply having to turn off the bike and let it cool down all the way to "blowing" the engine. The engine is not going to actually blow up, but all the gaskets and seals may not be able to take the heat. In extreme cases, you may even crack the engine block and that will usually mean a new engine. That is trouble that you don't want. It is much easier to just make sure that you have the proper level of coolant in the radiator.
How do you go about doing this? Ironically, it is the same way that you would with a car. As stated earlier, everything is on a smaller scale but it is the same. On most bikes the radiator will be in front of the engine, which makes sense because that is where it will get the most wind hitting it. As a foot note, radiators work by having cooling fins and tubes on the inside (usually made of copper but not always). As the hot coolant comes from the engine it will circulate down through these tubes. As the wind hits the cooling fins, it pulls the heat from the tubes that contain the hot liquid. It is then recirculated into the engine at a cooler temperature to take more heat off of the engine.
We are throwing around terms like "cool" and "hot". These temperatures we are talking about are in excess of 200 F. Since it is a sealed pressurized system, the temp can go above the 212 F mark for water to boil. This means that even if the motor is "cool" it can be hot enough to remove skin from your body.
Ok, so how do you add coolant to the motorcycle? With the bike sitting (upright on the center stand if possible) and not running, and nor been running long enough that it is "cool", take off the cap to the radiator. Pour coolant into the neck (it will be a short tube like part that sticks out above the rest of the radiator). This may be on the left, right, or even center depending on the style of bike. Once you have filled the radiator to the top, put the cap back on. Remember, it is a sealed system so there is more to it than just screwing it on. Most of the time you will have to turn it while pushing down at the same time (similar to the lids on child proof medicine bottle). The reason for this is to stop the radiator cap from blowing off if the pressure builds too much.
Once the cap is on securely and correctly, go ahead and start the motorcycle. Let it run for a few minutes (maybe 10) and shut it off. By only letting it run for a short time, you are not allowing the temperature to get hot enough to harm you when you remove the cap. Even so, be very careful when removing the cap. Make sure you are wearing gloves, have long sleeves, eye protection, and are not standing directly in front of the cap.
The coolant level will have gone down. This is normal. When you started the bike, the liquid was circulated throughout the engine. This is the time that you want to top off the coolant level. After you have done this, replace the cap. Make sure that it is on tight. If it isn't, then you are defeating the entire concept of having a closed pressurized system.
That is all there is to adding coolant to a motorcycle. While it is just as important as the fuel or the oil, it is often overlooked. Without it, you may find yourself replacing an engine. When you are doing your routine maintenance, don't forget to check the level of the coolant.
If you happen to be an all weather rider, and live in a cold climate, antifreeze can come into the equation but that is another story all together.
