What to Do When a Dirt Bike Won’t Start – 10 Things You Need to Do

Quite often I meet people who are stranded since their dirt bikes can’t start. Thus, I did some research to determine some of the things that you can do if you find yourself in such a situation.

So, what are you supposed to do if your dirt bike won’t start? Well, before you rush to the mechanic, you need to inspect your dirt bike to ensure that everything is okay since it could just be a slight issue.

Sometimes, something as simple as an empty gas tank can be the culprit. In other times, it can be something complicated, and you will have no other option apart from taking your bike to a mechanic for extensive troubleshooting.

I understand the fact that there is nothing more disappointing than gearing up for a day of riding only to find out that your dirt bike won’t start. Things might even get worse when it doesn’t start, and you have no clue as to why.

You can kick all you want and do whatever you want, but the fact remains that unless you address the real issue, you won’t go anywhere. This is one of the top reasons why routine maintenance is essential.

If you are doing everything that is required of you, then you don’t have to worry about anything since your bike will always be in good condition and ready to fire up whenever you need it. I have prepared a list of the top ten things that you need to do if your dirt bike won’t start. Read on to find out.

Check the Fuel

You may be struggling and doing whatever you can to fire up your dirt bike when the gas tank is empty. Even if you are certain that the gas tank is filled, recheck it.

You can either shake your dirt bike gently while keeping your ear close to the tank or peak inside the gas tank if you can. If there is fuel inside the tank, be sure to check the carburetor.

An easy way of checking if your carburetor is getting fuel is simply by opening the overflow located at the bottom of the float bowl. If any liquid comes out, it means that everything is okay and the fuel is getting to the carburetor.

However, if nothing comes out, then it means that the fuel valve is probably turned off. If everything is okay, think about the last time that you filled your gas tank. Remember the fact that old fuel can sometimes clog your system. If your fuel system is clogged, the only thing that you can do is to clean your entire fuel line.

Check the Spark Plug

Another simple thing that can make your dirt bike fail to start is when you have a bad spark plug. If this is the problem, then you are lucky since the only thing that you are supposed to do is to replace it and everything will be okay.

Replacing the bad spark plug with a good one should take you about one minute. Make sure that your stock of supplies will always have a new spark plug that you can easily use in such situations.

Unfortunately, the problem of a bad spark plug isn’t that common, especially in four-stroke bikes. Furthermore, your routine maintenance should catch this issue before it becomes a significant concern.

Sometimes, the spark plug may be okay, but the connections to it are faulty. Therefore, be sure to check both the spark plug and the connections to it to ensure that everything is okay before you move to the next step.

Check the Stator and Coil Pack

Apart from the spark plug, the stator or coil pack problems are other common ignition-related issues that may cause your bike to fail to start. If you check both of them and discover that they are okay, be sure to check the kill switch as well.

You need to keep in mind that the stator of a dirt bike acts much like an alternator or generator. It works with the coil pack to ignite the spark plug. Therefore, if the spark plug can’t seem to ignite, there could be a problem with any of these two components. A faulty kill switch could also be a culprit in this case.

Therefore, make sure that you also check it out and ensure that everything is okay. A faulty kill switch may also prevent your dirt bike from shutting down.

Clean Your Air Filter

If you have got a dirty air filter, your dirt bike may not start no matter how hard you try. A dirty air filter results in a fouled spark plug, and that could be a significant problem that you need to deal with.

If you haven’t checked your air filter for some time, be sure to inspect it and ensure that it is clean before you proceed with your troubleshooting process. To access the air filter, remove the seat or side panel.

Once you have removed the seat or side panel, remove the clip or center bolt that secures the filter element to the air box. If you need any extra help accessing the air filter on your dirt bike, be sure to check your service manual or check out the manufacturer instructions.

While at it, you should also check the air tract to ensure that it isn’t clogged. Checking your air filter is a simple task that shouldn’t take you a lot of time.

Check the Battery

If everything seems to be in perfect order, but still your bike won’t start, the most likely culprit at this stage is the battery. It could be a faulty battery or something that is preventing the battery from doing its job right.

Some of the other familiar signs of a dead or faulty battery include a weak horn, dim lights, and slow starter activity. Try to push your horn, and if it sounds weak, the battery may be the culprit. If that is the case, you may have to charge your battery or replace it if it is dead.

However, before you proceed to charge or replace your battery, be sure to check its terminals since they may be loose or corroded. If that is the situation, all you have to do is to clean or tighten the terminals, and you are good to go.

After cleaning or tightening, make sure that you take the readings across the terminals. If the voltmeter records less than 12.5 volts with no load or 11.5 volts when the lights are on then consider recharging it.

Charging your battery may take some time. If you are in a hurry, you can jump-start your bike and charge it later.

Make Sure that the Fuel/Air Ration Is ON

If you are riding a carbureted dirt bike, you need to check and ensure that the fuel/air ration isn’t turned OFF. Too much fuel or too much air usually prevents the engine from firing. If you stall your bike after it has been running, you need to keep in mind that you will need a hot start to fire it into life the next time you want to go out riding.

I know you are surprised, but the truth is that it is pretty easy to flood a cold engine by simply transporting your bike. Perhaps, you rolled your throttle unknowingly hence flooding your engine with gas if your dirt bike has a hot start, it is worth to try it and see if everything becomes fine.

Check for Proper Compression

You can conduct a simple test on your dirt bike to establish whether it has adequate compression or not. This test will also help you to know about the engine status of your machine. First, you need to make sure that your engine is completely off.

Anyway, I don’t expect it to be ON since your bike can’t start. The next thing that you are supposed to do is to hook up your compression gauge, carefully open your throttle and start turning your engine over until the time the psi indicator dial will stop moving.

Experts recommend that your cylinder must have 100 psi for your dirt bike to start successfully. If you don’t have the compression gauge and you suspect that this might be the problem, take your bike to a mechanic who will perform the compression test on your dirt bike at a little cost.

You need to be careful while performing this test to avoid causing any further damage to your bike.

Fuel Injection Issues

I need to caution you that troubleshooting your fuel injection system will require quite expensive and specialized equipment. My advice here is to tread carefully and if you think that you aren’t up to the task, take your bike to a mechanic for troubleshooting.

This territory requires highly trained and experienced experts. You need to keep in mind that the fuel injection system usually works at extremely high pressures and if you get in front of a working injector, you may hurt yourself.

The good news is that fuel injectors rarely fail and it is usually the pump that will be faulty. Most dirt bike fuel injection pumps tend to run for a few seconds whenever the key is turned on to pressurize the entire system.

Try to listen to yours over time and learn how it sounds when the bike is in excellent condition. If your bike doesn’t start, listen and see if you can hear the pump running. If you can’t hear anything, be sure to check the pump fuse.

As a last resort, try to crank the bike’s engine while spraying a brief burst of standard carb cleaner into your air intake chamber. If the bike starts and the engine runs, then you should know that your fuel injection system is faulty.

Check the Integrity of Every Electrical Connector on Your Dirt Bike

Don’t think that this is a lot of work since a dirt bike doesn’t have a lot of electrical connections. The wires plugged into your bike’s coil are easy to knock loose when you are removing or replacing your fuel tank, and this could be the issue if your bike can’t start.

Inspect all the electrical connections and look for obvious tears, cuts, or burns in the wires between various connections. Remember the fact that a minor cut on an electrical wire can have significant implications on the entire connection. If you notice anything unusual, make sure that you replace the affected wire.

Use Choke

If you haven’t used your dirt bike for some time or the weather outside is extremely cold, and it can’t start, the best thing to do is to try and use the choke to fire it up.

The primary purpose of the choke is to enrich the air-fuel mixture to help start your cold engine faster. The primary reason why you should turn to the choke is that a cold engine won’t vaporize the fuel in the air-fuel mixture more quickly.

When you close the choke, you will effectively reduce the volume of combustion that enters into the cylinder which transforms the air-fuel ratio to a rich mixture.

More fuel in the mixture than normal will help the dirt bike to achieve ignition hence firing the engine to a start. Once your engine starts, remember to turn off the choke and enjoy your ride.


If you have done all this and still you can’t get your engine roaring into life, then it might be time to take your dirt bike to a mechanic for thorough troubleshooting.

However, if you understand the engine and how it works and you want to try it yourself, you should first check the piston area and the vacuum seal. This is usually a common problem in older bikes and mostly occurs due to lack of proper fuel maintenance over a prolonged period.

 For your bike to function smoothly, all parts must be working in harmony. The spark plug should be faultless, a full tank, proper compression, and clean air are all essential to a successful start.

The good thing is that you don’t need to be a mechanic to learn basic engine care practices and simple maintenance tasks that could save you a lot of money in the long run. ffff

Daniel Mose

Daniel is a big fan of dirt biking. I own KTM 250 SX-F. I love learning how to maintain this dirt bike and ensure it lasts long while serving me without any issues. Join me in this journey as I document stuff that we, as dirt bike lovers, ought to know.

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