Can You Jump Start A Motorcycle With A Car?

You’ve probably all have heard different do’s and don’ts when it comes to starting a motorcycle. Some are true, but some are just old wives tales. Recently we’ve outlined different ways to start a motorcycle, specifically on how to push it, whether you’re fuel injected or carbureted.

Push starting your motorcycle is a great option, but sometimes if the battery is dead enough, even a push start won’t be able to get it to turn over and you’ll need to resort to using other vehicles to help you get your motorcycle started again.

So, can you jump start a motorcycle with a car? It is possible to jump start a motorcycle with a car if it is performed carefully. This method should only be used sparingly since there are some risks involved for the motorcycle. To do this, ensure both vehicles are off. Starting with the motorcycle, connect the positives first then connect the negatives. Start the car, wait, then attempt to start the motorcycle.

Motorcycles and other sporting vehicles usually have batteries that are much smaller capacity than cars. So, how do we properly start a motorcycle with a car? What should be stay away from? Are there ways to check to see if damage was done after the motorcycle is started? Keep reading for a full explanation.

Why (And When) It’s Okay To Jump Start A Motorcycle With A Car

A lot of people recommend staying away from jump starting a motorcycle using a car battery, and generally I agree with this statement. Using a car battery can cause damage, so before you try to use one, make sure that you’ve tried other methods first.

If you don’t have a way to start your motorcycle other than your buddy’s car and some jumper cables, then proceed with caution. This can be done safely when it’s done right; a car can give off more power than a motorcycle needs, but nonetheless has power to give. When given the right amount of power, a motorcycle with a dead battery can be good as new.

If the battery that is on your motorcycle is a 12 volt system, and the one that is in the car is also a 12 volt system (which most of them do), then charging your motorcycle should be relatively easy and pretty effective. So, if you’re stuck and only have a car and some cables, don’t be afraid, but instead be cautious and make sure that you do it right.

How To Jump Start A Motorcycle With A Car

The first step when jump starting a motorcycle is making sure that you know why it won’t start. This means to make sure that it has gas, that the switches are turned correctly, and that the kickstand/ gear selector are in the right positions. You can see our other article here that can define other reasons why a motorcycle won’t start.

If you’ve narrowed it down to battery failure, then you’re ready to take the next step which is seeing if you can push start your motorcycle. Make sure you have space and that the computer is able to turn on, and then try to give your motorcycle a push start. Click here to learn more about how to push start a motorcycle.

After you verified that your motorcycle’s battery is dead and that you’re only left to use a car, let’s make sure that you have it set up right. First, make sure that the car and motorcycle are BOTH turned off. Find some jumper cables and have the batteries near each other. For the cables that you use, it’s recommended to use motorcycle specific cables. You can use car cables, but keep in mind that to reach your bike’s terminals, it might be difficult with the size of the car clamps. 

Once you have the cables out, start with the motorcycle. Connect the positive side of the batteries together, and then connect the ground side of the batteries. Remember, red is positive and black is negative.

The reason you want to do it in this order is so that you don’t accidentally short out the car’s battery and are left with no way to start either the car or the motorcycle. When you connect the ground side of the motorcycle, try to not directly clamp it to the terminal of the battery. Put it on some exposed metal on the frame or the engine of the bike. This can give a safer charge, and again, helps to make sure that you don’t short out either battery. 

Once the battery is connected, don’t do anything. This is different than when you are jump starting a car. With jumpstarting a car you want the good car battery to be running and maybe even revving the engine to help charge. A motorcycle is going to be a little different since the battery is much smaller. Initially you should just simply connect the two without starting the car and see if it charges the motorcycle battery. 

After the car and the motorcycle have been connected for about a minute, go ahead and turn the key to the motorcycle and make sure that everything illuminates. If it does then it’s time to try to start up the motorcycle.

When you crank the motorcycle, only let it crank for a second or two. If it doesn’t start, turn everything back off and let it charge up a little bit more. Because of the amps that are pulled from the car battery, you want to make sure that you don’t have it trying to turn over for too long.

If your motorcycle still doesn’t start after letting it charge from the car battery, you may try turning on the car and let the motorcycle battery charge for a minute or two before trying to start the motorcycle.

When the motorcycle starts up, go ahead and disconnect the cables. You should do this by removing them the opposite way you placed them, starting with the negative cable grounded on the motorcycle.

You might notice that when it starts up it’ll sound more aggressive than it normally does. Don’t worry about that. Using a car battery might cause the starter to engage more quickly than they normally do. Just remember that as soon as the bike starts up, take off the cables and let it sit and idle or go for a ride in close quarters for a few minutes to make sure that the charge is good.

After all of this is said and done, make sure you can take your motorcycle somewhere to get checked out. Because the batteries on motorcycles are smaller than cars, they can become very worn after being fully discharged. Checking the battery is very simple, and should only take about 20 minutes.

Here’s our YouTube video that gives a better visual on how to do this.

https://youtu.be/0nAHIQllU5s

Is It Bad For A Motorcycle To Start This Way?

It’s hard to say whether it’s a bad thing or a good thing to jump start your motorcycle using a car. Will this make sure your motorcycle starts up and gets to where it needs to be going? Yes.

However, incorrectly connecting the jumper cables can cause electrical shorts or sparks which can ultimately damage the motorcycle’s electrical systems.

Additionally, if the motorcycle battery is severely discharged, the high charging current from the car’s alternator can overcharge the motorcycle battery, leading to damage or a reduction in the lifespan. It’s like trying to cram a bunch of things in a small bag quickly.

Things To Avoid When Jump Starting A Motorcycle With A Car

When jumpstarting a motorcycle using a car, you’ll want to make sure that you have the right jumper cables available. Like I said, car cables will work, but due to their size, it might be very difficult to attach them to the terminals on the motorcycle battery, so make sure that you carry around a pair of motorcycle jumper cables under your seat.

Also, make sure that you don’t try starting the motorcycle for longer than just a couple seconds at a time. If you hold the start button for too long, you will probably fry your starter motor, and then won’t be able to go anywhere!

Conclusion

Jumpstarting a motorcycle using a car is certainly an option when you’re in a pinch! However, this process must be done correctly to prevent damage to both vehicles. Ensure you connect the jumper cables correctly and in the right order to prevent electrical shorts.

Having done this several times myself, I’ve seen first-hand the effectiveness of this method and how helpful it can be. This has especially been helpful for me since I normally buy and restore older motorcycles that tend to have battery issues. Feel free to reach out if you have any questions or comments about this, I’m always up for discussion!