This guide will help you troubleshoot the most common causes for an ATV that won’t start. Some issues are easy to fix at home, while others require assistance from a mechanic.

Choose the topic that describes your ATVs behavior the best.

The ATV won’t start – the engine is not turning over

If your ATV doesn’t crank at all when you’re trying to start it, there are a few basic things to look into. 

Make sure the kill switch/run switch is in the “ON” or “RUN” position. 

You’d be surprised how often the solution to an ATV that won’t start is forgetting to turn on the kill switch.

Also, if your ATV has a tether pull cord style kill switch, make sure it is connected properly. 

Make sure the ATV is in “Park” or Neutral

Many ATVs are designed not to start when in gear as a safety precaution. 

Make sure the battery is charged

The battery should read 12,6 – 12,8V. Use a multimeter or a voltmeter to check the voltage.

If the voltage drops too low, the battery won’t have enough charge to start the bike. 

Charge the battery or replace it if it’s dead. Am easy way to test your battery is by checking the voltage-drop with a multimeter as you try starting the bike. If your fully charged battery drops below 11,5 volts under load (while you crank the starter), it needs to be replaced. 

Check the main fuse

Most ATVs have a main fuse. Your user manual will help you locate it.

If your battery is charged, but you still get nothing when turning the key, you may have a blown main fuse. Replace it with the right size fuse and try starting again.

Make sure the solenoid is getting power

The solenoid works as a switch that sends a high current to your starter when you push the start button or turn the key. For it to work you need to make sure it is getting power from the battery.

The solenoid should make an audible “clicking” sound each time you hit the starter. If it does, you know it is getting power and the problem is likely with the solenoid itself or possibly the starter. Solenoid and starter issues will be covered later in the post. 

If you do NOT hear a clicking sound, you can use a multimeter or voltmeter to verify that the solenoid is in fact not getting power.

The solenoid is usually located near or on the starter.
  • Put your multimeter to DC Voltage.
  • The red lead goes to the battery (red) side of the solenoid.
  • The black lead goes to ground.
  • You should get a voltage reading of 12V or more.

If you don’t get a reading, you need to trace the wiring back to your battery to wind where the connection is broken. Look for loose or corroded terminals or shorts from damaged cables. 

The ATV won’t start but turns over

A gasoline engine needs three essential components to start and run:

  1. Gasoline
  2. Spark
  3. Air (compressed)

First, check if the bike is getting fuel:

  • Locate your spark plug. You may need to remove a few plastic covers to find it.
  • Remove the spark-plug wire (on a carbureted ATV) or the ignition coil (on a fuel-injected ATV) from the spark-plug.
  • Remove the spark-plug from the cylinder head using a spark-plug removal tool.
  • If the plug it’s wet, you know the bike is getting fuel.

If the plug is dry, the bike is not getting fuel and you need to continue the troubleshooting as described below.

Next, check for spark:

  • Install the spark plug back into the cylinder head.
  • Connect an inline spark-tester between the spark plug and the spark-plug wire/ignition coil. You can get one for cheap at most auto supply stores.
  • Make sure the run switch is in the “ON” position.
  • Keep your hands clear of the test tool and the area around it.
  • Push the starter button.
  • The test-light on the spark-tester will light up if there is a spark.

Alternative method: If you don’t have a spark tester tool, you can do a visual test to check for spark. Please note that this method may cause electric shock if done incorrectly.

  • Remove the spark plug from the cylinder-head and connect it to the spark-plug wire or ignition coil.
  • Grab the plug wire and hold the plug about 1/8th of an inch away from the cylinder head. Make sure you are only touching the rubber, and not any metal parts.
  • Activate the starter.
  • As the motor turns, you should see repetitive bright blue spark arching from the spark plug to the cylinder head. 

You will find the proper steps for troubleshooting an ATV that is not getting a spark further down this post.

The ATV is not getting fuel

If the spark plug is still dry after cranking the engine for a few seconds, you know that fuel for some reason is not getting to the cylinder.

Most times, it’s either an issue with the fuel-pump or that the fuel supply line is clogged up somewhere between the gas tank and the carburetor. 

Old or unstabilized gas tends to gum up over time and may create a clog. Dirt and debris getting inside the tank is another common culprit for a clogged up fuel supply.

The easiest way to identify the cause is through a process of elimination.

Note that if you find contamination such as dirt or gummed up fuel at wone spot, the whole system is likely dirty and needs a complete clean for the best result.

The steps involved are a bit different depending on whether your ATV has EFI (electronic fuel injection) or a traditional carburetor system.

Both carburated and fuel injected ATVs: Make sure the gas cap vent is not clogged

There is either a vent in the gas cap or a separate gas tank vent tube. Make sure neither is clogged and allows air to flow freely.

Fuel needs to be replaced with air as it gets pumped out and used. If the vent is blocked, the fuel pump may not be able to suck fuel out of the tank.

Troubleshooting a carbureted ATV that is not getting fuel

Older ATVs, and some of the cheaper models still today are designed with a traditional carburetor fuel-system.

Make sure the fuel shut off valve is in the “ON” position

There should be a shut off valve at the lowest part of the fuel tank. Make sure it is turned on.

Check if the carburetor is getting fuel or not

This step will help you narrow down the possible causes of why fuel is not reaching the cylinder.

With the fuel valve open, disconnect the fuel line from the fuel inlet of the carburetor. Turn over the engine to see if gas is coming through the fuel line. 

If it is very little or no fuel coming from the fuel line, you likely have either:

  • A clogged up or faulty shut-off valve.
  • A clogged up fuel filter.
  • A fuel-pump problem.
  • A clogged gas cap or gas tank vent.

If there is a steady or pulsating stream of fuel you know that

  • The fuel pump is ok.
  • Fuel flows all the way undisrupted from the tank to the carb. 
  • The problem is likely a dirty carburetor.

Continue your troubleshooting based on the results of this initial test. 

Check if the shut-off valve screen is clogged up

Fuel exits the fuel tank through a shut-off valve at the lowest part of the tank. Inside this valve, there is a mesh screen that is supposed to stop dirt and debris from entering the fuel lines. 

Disconnect the fuel line from the valve to see if gas comes through. If fuel does not flow freely, you need to remove the valve to clean it. 

All of the fuel left in the tank will drain as you remove the valve. Use a bucket to collect the fuel.

Use carb cleaner, some fresh gas, and a toothbrush to clean the valve and mesh screen. Pour some fresh gas in the tank to flush out any remaining gummed up old fuel or debris before installing the valve.

If the gas in the tank is old or contaminated, you should not put it back in the tank after cleaning the valve. 

Check if the fuel filter is clogged up

Not all ATVs have serviceable fuel filters, but some do. 

Trace the fuel line all the way from the fuel tank to the carburetor. Look for a cylindrical canister unstalled in-line anywhere on the fuel line. 

Fuel filters are cheap and easy to replace, so it’s worth doing if you suspect that something is disrupting fuel flow. 

Troubleshoot a fuel pump that is not working

ATVs with traditional carburetors usually have a vacuum-operated fuel pump. They are run by vacuum/pressure pulses created in the crankcase. The negative pressure pulls fuel in, while positive pressure pushes fuel out. 

  • Locate the pump by tracing the line coming from the gas tank.
  • There are three rubber hoses attached to the pump. 
    • One is fuel coming from the gas tank
    • One is fuel exiting the pump and to the carburetor 
    • One is the pulse-line (air), usually marked with a “P”
  • Disconnect the inlet fuel line and position it lower than the fuel tank to make sure gas flows undisrupted from the gas tank. 
  • Reconnect the inlet fuel line.
  • Inspect the vacuum line for any damage or cracking and replace it if necessary. Leaks will prevent the pump from working correctly.
  • Make sure the pulse line is connected correctly both at the pump and by the crankcase. 
  • Make sure the engine oil isn’t overfilled. This may cause some oil to get trapped in the pulse-line, obstructing airflow. 
  • Also, inspect the fuel lines going from the fuel tank to the fuel pump. If there are any signs of weather cracking, replace the line. Cracks in the fuel line may cause the pump to suck false air into the tube instead of gas. 
  • If you have a vacuum gauge, connect it to the vacuum. The gauge should follow the pulses. If there is no vacuum, there may be internal problems inside the engine like a stuck valve. Fixing such issues is usually a job for a mechanic. 

If the pump is still not working, you may need to replace it.

Alternatively, you can pull it apart to give it proper cleaning and a rebuild. Inside there are check-valves that may get suck if dirt enters the pump. There is also a rubber diaphragm that may stretch or crack over time.

Test a vacuum-operated shut off valve (petcock valve)

Some ATVs have a vacuum-operated shut-off valve that is designed to open only when the engine is running.

Identify the vacuum line that goes to one of the inlet ports. Disconnect the line and draw a vacuum to the disconnected port. The valve should now open and allow fuel to flow. 

Inspect the vacuum line to make sure it is correctly connected at both ends and has no cracks that will draw false air. 

If you suspect that the valve is not working, put it in “prime” as this will override the vacuum operated valve. This will tell you if the valve is working or not.

Clean the carburetor

Old unstabilized fuel and debris from the gas tank may completely gum up the carburetor or block the jets so that the engine is not getting any fuel. 

I recommend using a product like Seafoam or similar to see if it will dissolve the gummed-up fuel before embarking on a more thorough cleanse. Leave the choke wide open to allow maximum flow. 

Click this link for instructions: https://seafoamsales.com/uploads/2018/12/HOW2_Gummed-Up-Carburetor.pdf 

If Seafoam doesn’t work, your best bet will be to remove and disassemble the carb to clean it properly. This job may not be for everyone. Consider asking a mechanic if disassembling the carb seems intimidating. 

  • Start by draining the carburetor. There should be a drain screw at the bottom of your carb bowl.
  • Disconnect the carb from the ATV and move it over to a tidy workbench. You do not want to be missing any parts when reassembling the carb.
  • Disassemble the carb. Take photos as you remove parts to keep track of where things go. 
  • Use carb cleaner and a toothbrush to clean as much as you can.
  • Use an air compressor with a nozzle to clean all the small passages inside the carb. 
  • Remove both the main jet and the pilot jet. Make sure you can see the light coming through it. If you are not able to clean the jet, it’s best to replace it. Make sure the float assembly is pulling up the float needle and is not stuck.
  • Reassemble the carb and install it to the ATV.
  • You will also need to address the cause for your dirty carburetor, or it will clog up the next time you ride. Drain or siphon all of the old fuel out of the gas tank. Flush the tank with some fresh gas. Replace any fuel filters as well as they are likely just as dirty as the carb. 
  • Consider adding a cleaner product such as “Seafoam” to your first tank of gas after the cleanse. This will dissolve any gummed up fuel still trapped in the system. Follow the manufacturer’s instructions, depending on which cleaner product you choose to use. 

I recommend these links for a more detailed and illustrated guide on how to disassemble and clean a carburetor (external links):

How to disassemble and properly clean a carburetor: 

https://www.rockymountainatvmc.com/rm-rider-exchange/clean-carburetor-motorcycle-atv/    

Clean a carburetor by using chemical carb cleaner: 

Troubleshooting an EFI (electronic fuel injection) ATV that is not getting fuel

Fuel-injected engines use an electronic pump to feed pressurized fuel through fuel injectors and into the engine. 

Troubleshooting a fuel-injected ATV is a bit trickier than carbureted ATVs, but it’s possible:

Make sure the internal fuel filter is not clogged

Most fuel injected ATVs do not have a serviceable fuel filter.

Instead, they have a non-serviceable screen or a sump-filter located inside the gas tank. Note that some EFI ATVs also have an inline external fuel filter.

The screen or filter is one component of the complete full fuel pump assembly, located inside the tank. These filters are not meant to be serviced, but may still clog up. 

You need to remove the whole fuel pump assembly to access the filter.

Begin by removing any plastic covers to access the top of your gas tank. There you will find a large plastic locking-ring that connects the entire fuel filter assembly to the fuel tank. You may need a set of large pliers to remove the ring as they tend to bind. 

Be careful so that you don’t damage any of the fragile plastic components as you remove the pump assembly. 

The filter will be at the very bottom of the assembly. You will generally need to replace the whole assembly to replace the filter.

If you want to save some money, consider looking up a suitable replacement filter on-line.

EFI fuel pump troubleshooting

Electric fuel pumps tend to fail for no apparent reason from time to time. Before they break completely, they may be getting weaker gradually due to wear. 

A worn fuel pump may not be able to create a high enough fuel pressure for the injection system to mist the fuel properly, which in turn may prevent the ATV from starting. Aftermarket fuel pumps are available for most ATVs, but replacing them is not for everyone.  

In addition, you have possible fuel pressure regulator issues or bad o-ring seals. 

The best way to test an electric fuel pump is by measuring the fuel pressure at the fuel rail. This will, however, require a specialist tool that the average home mechanic does not have.  

A clogged fuel filter or clogged fuel lines may cause a too low fuel pressure as-well. 

Before replacing the fuel pump assembly, it’s worth making sure the bike is charging correctly as a low voltage will negatively impact fuel pump performance.

Troubleshooting fuel injector problems

Modern EFI ATVs may provide an error code indicating fuel injector issues.

The task if troubleshooting fuel injector problems, however, is a task that often gives even seasoned mechanics a headache. I recommend you leave this job to a dealer. 

The ATV is not getting a spark

Here are a few things to try out if your ATV is not getting a spark:

  • Make sure the kill switch is turned “ON.”
  • Test if the kill switch works by using a multimeter, a test light, or a simple continuity tester. Poke one probe into each of the two cables going into the switch. There should be no continuity when the switch is off, and continuity when it is on. 
  • Check for unplugged or damaged wires in the wire harness.
  • Replace the spark plug; it may be damaged even if it looks ok. 
  • Test the internal resistance of the ignition coil. Use a multimeter to check for internal resistance between the positive and negative terminal. Set the meter to 200. You should get a reading of 0-2 ohm. Over 2 ohms, the coil is likely bad and needs to be replaced.
  • Test the resistance between the positive terminal of the coil and the spark plug. Set the meter to 200.000. You should get a reading of 10.000 – 25.000 ohms. Any reading outside of this range indicates that you likely have a bad coil.
  • Finally, check if the stator is working properly. You will find a method for testing the stator in this post

The ATV won’t start – it just backfires

When you try to start the ATV, the engine seems to crank just as normal. But the engine will not start. All you get is one or several loud bangs coming from the exhaust.

These bangs are known as the ATV backfiring, which is usually caused by the air/fuel ratio being too rich or too lean.

The ATV has become flooded

If you forget to engage the kill switch before trying to start the bike, it will pull gas into the carburetor, but there is no spark to ignite the fuel.

When too much gas enters the carburetor, there won’t be enough space left to mix the required air/fuel ratio for the bike to be able to start and run.

If you have the time, let the bike sit for a couple of hours before trying to start it again.

Alternatively, you can remove the spark plug while turning the engine over for a few seconds. Any excess gas will escape through the spark plug hole. Wipe the plug clean and put it back in. Then try starting the ATV as usual.

The spark plug has gone bad

Spark plugs are considered consumables that may need replacing from time to time. A spark plug that has gone bad may prevent the ATV from starting and only cause it to backfire. 

Replace the plug with a new one according to the manufacturer’s specifications. 

Clogged air filter

A clogged air filter will restrict airflow and therefore have a significant impact on how rich your ATV engine operates. Too little air will cause an overly rich mixture, which may result in symptoms as the ones you experience.

Clean or replace the air filter with a new one, before trying to start the bike again.

Incorrect valve clearance

Another possible cause of these symptoms is that your valve clearance is incorrect. As the engine gets some hours to it, the valves may seat deeper in valve seats and may need adjusting.

Checking and adjusting the valve clearance on an ATV is not that hard to learn, but it is recommended that you ask for guidance from someone more experienced the first time you do this job. If you do it incorrectly, you risk causing permanent damage to your engine. 

The timing is off

Your bike’s timing is what tells the bike when to pull air and fuel into the cylinder, when to ignite the fuel and when to discard exhaust gasses out the exhaust. If one cam is off by just one tooth, you may run into starting issues accompanied with the occasional backfire.

If you’ve been working on or removing some of the timing components, you need to make sure that everything is reassembled correctly. Lookup a timing diagram for your specific ATV and make sure all the timing marks line up. 

If the task of aligning the timing marks sounds intimidating, you are probably better off leaving the job to a mechanic.

Sheared flywheel timing key

The timing might be off even if you did not work on any of the timing components. What often happens is that the timing advance key, also known as a rocket key, has sheared and needs replacing.

The timing key plays a crucial role in timing your bikes ignition as it locks the flywheel in the right position on the crankshaft. If it breaks, your bike’s timing will be off immediately. 

This little metal part is designed to break to protect other engine components. From time to time, it may break even if there is nothing else wrong.

Luckily they are not that expensive or time-consuming to replace. It is not a job everyone will be comfortable doing for themselves, but it is nothing an averagely skilled home-mechanic can’t manage after watching a couple of youtube videos for their specific brand and model.

The key is located on the crankshaft. To access it, you need to unbolt and remove both the flywheel-cover and flywheel (the flywheel on an ATV is actually called a generator). A flywheel puller may be required.

If the key is sheared, remove all pieces from the old timing key and install a new according to factory spec. Ask your dealer to make sure you get the right one. Install the flywheel and flywheel cover before trying to start the bike. 

Make sure the timing marks are lined up correctly. The timing mark layout will be different from model to model. Please refer to your service manual.

The carburetor has become dirty

A dirty carburetor may prevent enough fuel from getting to the cylinder, causing a lean backfire. 

Due to the backfire, you know that at least some fuel is getting through. Please refer to step 3 on how to clean the carb. 

Bad or contaminated fuel (water in the gas)

Before spending money on a mechanic, it may be worth draining your gas tank and adding fresh gas. Gas may go bad if it sits too long, or it may get contaminated with water due to condensation.

Most gas tanks will have a removable drain plug or on/off switch at the bottom. Your next best option is to pump or siphon the fuel out of the tank.

Low compression

If a valve has stuck open, the compression will be too low, and the bike will not start. Repairing a stuck valve is usually a task for a trained mechanic.                                                           

The ATV won’t start – it just buzzes

If all you hear when turning the key is a buzzing sound, it is usually because your battery is dead or needs charging. 

The buzzing sound you hear is coming from the starter solenoid relay that won’t kick in due to low voltage. 

The solution is usually quite simple. Charge the battery or replace it if it is dead. 

Also, make sure all of the power wires going from the battery to the solenoid are correctly connected and not corroded. Put a test light across the connection you are testing as you activate the starter.

If the problem is not battery-related, you may have a bad starter or even a seized engine, preventing the starter from engaging. After ruling out a bad battery, it’s recommended to have further troubleshooting done by a mechanic. 

The ATV won’t start – it just clicks

When activating the starter, the engine won’t turn. All you can hear is a clicking sound each time you press the starter button. The clicking sound is coming from the starter solenoid.

Probably a bad starter

Bad or corroded solenoid

A solenoid that is working correctly will provide an audible click as you activate the starter. But the solenoid may be bad even if it clicks due to internal corrosion. 

Use a multimeter to test if the solenoid closes the circuit as you try activating the starter. 

Put your multimeter to DC Voltage. The red lead goes to the starter side of the solenoid. The black lead goes to ground. There should be no reading when not pressing the starter button. But when you activate the starter, you should get a voltage reading of 12V or more. 

If you don’t, your solenoid is probably bad and needs replacing.  

As an alternative method, you can use a piece of cable to jump your solenoid. Make sure the cable you use can handle the high current. If the ATV starts when jumping the solenoid, you know that the solenoid is bad and needs replacing. 

Bad starter

If your solenoid is good, the problem is likely with the starter. Starters may wear out due to old age, or they may go bad from a busted seal that will allow oil or water to get inside of the starter.

To test the starter, you need to remove it from the ATV. It’s connected with a few bolts. You will also need to remove the cable coming from the solenoid. 

Use a fully charged battery, and a set of jumper cables to test if the starter will spin as it’s supposed to. First, you should use the positive lead to connect the positive battery terminal with the positive (red) starter cable. Then attach the negative lead to the negative battery terminal. 

Hold the starter firmly in place and complete the circuit by connecting the negative lead to where your starter ground to the engine.

The starter engine shaft should start spinning freely with no signs of drag or scraping. Replace the starter if it is bad. 

The ATV won’t start after running out of gas

After running your ATV completely dry, you may find that it won’t start even after filling it up with fresh gas.

If it was running fine before you ran it dry, your problem is likely fuel-related as running the bike dry will not cause damage.

The fuel pump needs more time

The fuel pump will need some time to suck up fuel after the bike has run completely dry. Fuel-injected ATVs, in particular, can be extra tricky.

  • Make sure the fuel tank is full.
  • Turn the key to the on position, leave it for a few seconds, before turning it off. Do not try to start it. Repeat this process a few times, as this will help to prime the fuel lines and fuel filter.
  • Then try running the starter for several seconds or pulling the starter rope until the bike starts. If the bike doesn’t start after running the starter for about 10 – 15 seconds or pulling the starter rope 15-20 times, you should stop and continue troubleshooting. 

Use the carburetor primer

Not all ATVs have one, but if yours has a primer pump, you should use it to pump fuel back into the carb manually.

Look for a button on the side of the carb that may look like a choke knob. You will need to pump it several times for it to have any effect.

Running the ATV dry have caused dirt to enter the carburetor

Switching to “Reserve” and letting the bike run completely dry may allow dirt and gummed up fuel that has set on the bottom of your gas tank to be sucked into the carburetor.

The same applies to gas contaminated with water, which is heavier than gasoline and will fall to the bottom of the tank.

Clean the carburetor, as described in step three.  

Pour some gas in the spark plug holes

Remove the spark plugs and pour a dash of gas into the spark plug holes. Reinstall the plugs and try starting the bike.

This will provide enough fuel so that the ATV starts and begin sucking fuel on its own. You may need to do this 2-3 times before you succeed. 

Blow air through the gas tank vent

Blowing with a steady pressure into the gas tank vent tube while running the starter may help the fuel to start flowing. 

Bad spark plug

Running the bike dry won’t harm the spark plug per se, but contaminated fuel may. You may need to replace your spark plug to get going again. 

Burnt out fuel-pump

Some ATV fuel pumps cant take being run dry. When run dry, the RPMs will go up, and the pump will burn out due to lack of cooling and lubrication from the fuel.

Try removing the pump and check for internal resistance with an ohm-meter. If there is no resistance, the pump is likely bad. 

The ATV won’t start with starter fluid

First of all, it is not really recommended that you use starter fluid on your ATV in the first place. Starter fluid evaporates very easily, and the vapor is highly flammable. Both you and the ATV can catch fire from a spark caused by a short.

It’s much safer, and just as effective, to carefully pour or spray some gas straight into the cylinder through the plughole. A couple of ounces should be enough before installing the spark plugs and starting the bike. 

As long as the spark plug is providing a bright blue spark, and fuel is entering the cylinder, you may suspect that your compression is not good enough. Use a compression gauge and check if the bikes compression matches factory spec. If it doesn’t, the engine might need an overhaul. 

If the spark seems weak, the problem may be with the pick-up coil. Look for cracks or any other visible damage. If the coil is damaged, replace it with a new one. Note that the coil may be bad even if you’re getting a spark. 

The ATV won’t start after washing

Most ATV manufacturers recommend that you do not use a pressure washer to clean your ATV, as this may damage electrical components. Instead, you should wash the ATV by hand using only a garden hose and mild soap. 

Here are a few tips to try if your ATV won’t start after washing it:

  • Washing may have caused grit to enter the kill switch or starter button switch. Open the switch and clean it with electronics cleaner. 
  • Water trapped inside the spark-plug booth may cause a short that will prevent the ATV from starting. Unplug the boot dry it thoroughly. Using a hairdryer will speed up the process. 
  • Leave the ATV in the sun to dry for a day or two before attempting to start it again. 
  • Open the airbox to drain any water and let the filter dry out. 
  • On a fuel-injected ATV, try spraying the injector with an electronic cleaner to expel any trapped moisture. 
  • Check if any water has entered the fuse box, causing shorts. 
  • Other electronics that don’t like getting wet is the coil pack and CDI/ECU box.
  • If you washed the bike while it was running, it might have sucked water into the carbs. Locate the drain plug on your carb and drain it. You may also need to replace your spark plug. Just a small amount of water may foul the plug instantly.
  • If too much water has entered the cylinders from running the bike when washing it, it may have damaged the valves or piston rings. 
  • Disconnect and apply dielectric grease to every electric connector as a preventive measure for future trouble-free washing!

The ATV is flooded and won’t start

I’ve dedicated an entire post on how to repair an ATV that’s been submerged in water

The ATV won’t start in cold weather

  • Start by making sure the battery is healthy and fully charged. If the battery is below 12,6V, it needs a charge to provide the necessary cranking power to start a sub-zero ATV.
  • Make sure the spark plug is healthy.
  • Clean the carb as described earlier in this post. A dirty carb may cause issues when it’s cold. 
  • A carbureted ATV may need a richer fuel mixture to start in the cold. Usually, it’s enough to turn on the choke, but you may need to install one size bigger pilot jet. Try giving it some gas when turning over the engine.
  • The intake valves may be tight. Remove the rocker cover and make sure the valve clearance is according to spec. 

The ATV won’t start with a new battery

You’ve just installed a new battery, but the ATV still won’t start.

  • Make sure the battery is fully charged.
  • Make sure the battery is installed correctly

Then, refer to the other topics in this post according to how your ATV is behaving. Does the engine turn over? Does it make clicking or buzzing sounds? Start from the top and work your way down if you are not sure where to begin.

The ATV won’t jump start

If you are not able to jump start your ATV, it may not be a dead battery that is causing your starting issues. Make sure you are following the proper procedure for jump-starting an ATV. 

The ATV won’t pull start

If the ATV starts with the electric starter, it should start with a pull starter as-well. I recommend that you begin troubleshooting as if the turns over but won’t start.