Why Won’t My Motorcycle Start In The Cold?


Few things are a larger enemy to motorcycles than cold weather. When the weather turns, everything on a motorcycle becomes more difficult. It’s harder to start, harder to brake, more uncomfortable to ride, and in several ways, it can be a lot less safe.

Today, we’ll focus on why motorcycles will sometimes struggle to start in the cold, and also look at some ways to make starting up a little bit easier.

So, why won’t your motorcycle start in the cold? A motorcycle may not start in the cold because of the battery since they don’t perform as well in lower temperatures. The capacity that the battery has is lower when the outside ambient air is freezing. Engine oil is another factor because it is thicker when it’s cold, and thicker oil can make it harder on the engine to start.

So, what does it take to start a motorcycle in the cold? Why does a cold battery make it harder to start? How can I make it easier for my motorcycle to start up when it’s cold outside? Will starting my motorcycle in the cold damage it? We’ll go ahead and look at all these different points and help make the winters a little less intimidating on your motorcycle.

Why Motorcycles Struggle Starting In The Cold

Like I mentioned earlier, the major reasons why a motorcycle doesn’t start in the winter are that the battery doesn’t contain sufficient charge, and/or the oil is too thick. But what does this really mean? Why is oil thick when it’s cold out, and why does a battery struggle to start a motorcycle in less than ideal weather conditions? 

Let’s look at the battery first. As we all know, batteries on motorcycles are generally all 12V batteries. Even though the battery is 12V, we should know that a fully charged battery is actually higher than that. If you were to measure it, you would find that it’s usually around 12.6 V.

On top of this, when the bike is running, the alternator usually keeps the battery charged at a much higher value, usually closer to 14, but this isn’t a how-to on measuring batteries.

What does the volt measurement on a battery have to do with its ability to start a motorcycle? Maybe not as much as you might think. There are generally two measurements taken off of a battery, the volts, like I mentioned, and the cold cranking amps, or CCA. Both of these values on a battery are important when looking at it’s ability to start the motor.

Cold cranking amps of a battery are what really determine a battery’s ability to start the engine. What this value is, is the amount of current that a battery is able to output. So, what’s the difference between volts and amps? The voltage of a battery is sort of like the water in a hose, but the amps are like the size of the hose.

If you decrease the size of the hose, you are able to speed the water up, and have it move faster. So, if we look at this in comparison to starting a motorcycle, we need to make sure that first, there’s enough ‘water in the tank’. Without enough ‘water’, we won’t be able to ‘fill the bucket’, or in this case, start the engine. The second thing that we need to make sure of is that the ‘water’ is able to flow out of ‘hose’ at a high rate of speed. If the ‘water’ just falls out, we won’t be able to ‘fill the bucket’. 

When the outside air drops, the CCA of a battery is affected. Usually batteries are rated to a specific amount of CCA, but if outside air temperatures are low enough, or maybe the battery is old, even a fully charged battery won’t be able to get an engine to turn over.

Just like batteries, oil is also affected by air temperatures. Oil is rated to a specific weight. If you have ever changed the oil in your car or motorcycle, you know that oil is measured by a weight and temperature rating. For example, you might see a 0W-30 or 5W-20. Without going into what all that means, it should be understood that with all manufacturers, you might have a different weight of oil.

The weight of the oil doesn’t refer to a kilogram or pound measurement, but weight of an oil refers to the thickness of the oil at a particular temperature. As oil heats up, it becomes thin, but as it cools off it becomes thicker.

If the oil in an engine becomes thick enough caused by colder temperatures, you might find it difficult to start your motorcycle engine. The thick oil will cause resistance in the pistons, which will in return will make it hard for the starter to turn the engine over. 

How To Start A Motorcycle During Cold Temperatures

All too often I’ve run into the issue of not being able to start my motorcycle because it was too cold outside. I’ve tried many ways to assist in this process and this is what I’ve found to be most helpful.

First, ensure that life of your battery is sufficient. Cold temperatures are brutal on batteries that are already failing and will likely give you trouble if it’s less than fully charged. You can use a multimeter to detect the voltage and make sure it has at least 12.2 volts. If not, you’ll need to charge it.

Warming up the engine will greatly increase your changes of your motorcycle firing right up, so if you have one, place a space heater next to the engine (at a safe distance) and let it blow on the engine for a few minutes. I’ve done this dozens of times and it helps immensely! For more information about how to start your motorcycle in freezing temperatures, check out our other article by clicking here.

How To Prevent Starting Issues When It’s Cold Outside

If you’re a committed year-round rider and have already been through a winter or two, then you know that winter/cold weather riding takes more effort than any other time of the year. One of the reasons winter riding is hard is because it takes a bit of prep work to make sure your motorcycle is ready to go riding.

The best way to make sure your motorcycle will start easily in the cold is by keeping it indoors, and by that I mean a garage, or some other type of shelter or covered area that can keep it away from the wind or other factors that can drop the temperature of the bike.

In addition, you could look at investing into a space heater. It doesn’t take much, but using a small space heater on the motorcycle while it’s in a garage is all it would take to keep it warm and able to easily start up. I’ve even found examples where people will place the space heater directly under the oil pan of the bike to make sure that the oil stays a nice consistency. 

But what if you don’t have an inside area to put it in? What if you live at an apartment or in a city, where indoor parking is hard to find? A good way to keep heat on a motorcycle outdoors is to use a cover. Make sure you have a weather proof cover as this can help keep wind or rain or snow from lowering the temperature of the engine and battery.

Additionally, you can try using a heated blanket. You can find blankets online that are heated and battery powered so you don’t have to worry about using an extension cord or some other type of power system. By wrapping the motorcycle in a blanket and keeping a cover over top of it, you’ll find that cold weather rides are lot less intimidating.

If you’re looking for tips on how to maintain a motorcycle that has to be kept outside during the winter, see our other article by clicking here.

Is It Bad For A Motorcycle To Start In The Cold?

Generally, it is not bad for your motorcycle to start it in the cold though there are a few exceptions. One, if you don’t properly store your bike, starting it in the cold may cause premature failure to the battery. Like I mentioned, CCAs are important, and when the battery is used outside of it’s optimal temperature setting, it might become worn down and fail sooner than if the motorcycle was stored properly in the cold.

Another possible scenario to look out for is that if the oil is too thick, it can cause some abnormal wear to items such as the piston rings and the oil pump from lack of lubrication. But generally, this is not something to be concerned about as it is rare for this to happen.

Cold weather riding can be just as great of an experience as warm weather riding as long as you take the proper precautions. Make sure you find a good way to store your bike, and make sure that you have the gear that can make the ride possible.

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