Pulling an ATV can be pretty strenuous work, especially if you’re starting it several times a day. Letting it idle all day isn’t a solution to the problem either.
The top 6 reasons an ATV will only start with the pull starter include:
- Faulty battery
- Loose/corroded battery cables
- Faulty starter solenoid
- Faulty starter motor
- Blown fuse
- Faulty starter circuit
In this post, you’ll learn all about the most likely causes of your no start, how to diagnose them and how to fix them.
A failing battery or power delivery issue is always high on the list of likely issues with an ATV that won’t start on the button. An engine must turn over at a min RPM (typically 400RPM) in order to create enough internal combustion chamber compression additional, sufficient crankshaft momentum is required in order for the stator and also the crank pickup to generate sufficient voltage.
And so without sufficient crankshaft speed, neither compression nor voltage will be optimal for starting the motor. Battery power, therefore, is critical for spinning the motor over, but just before we get into testing the battery let’s check and see if the main fuse is OK.
Check Main Fuse
The main fuse is easy to check and is a simple fix, so it makes sense to check it first. So, if you’re missing all lights from the dash panel, go ahead and check the fuse.
It’s usually located close to the battery. The fuse may be blown, dirty, or corroded. Using a fuse that’s too small will cause it to blow prematurely, so check your manual for the correct size.
You already know how important the battery is, it is crucial to the proper running of your ATV’s electrical system. Sure some ATVs will run without a battery, but that isn’t advised. The charging system is designed to charge a healthy battery, and when a battery isn’t present, it can fry mission-critical components like stator and regulator rectifier.
Your battery is designed to start your engine. The charging system takes over to supply the power demands of the bike when running, but also, and importantly to replenish battery power.
Testing battery Voltage
Go ahead and turn the lights on if they’re dim. You can bet you found your problem, a faulty or flat battery. If you have a DVOM, then go ahead and connect it up, set the meter to 20v DC – Red test cable to the positive (+) pole of the battery and the black test cable to the negative pole (-) of the battery.
Most ATVs are 12 volt systems. Some older bikes may run 6 volt systems. Either way, the voltage will be marked on the battery casing.
Hold the test leads firmly on the battery and record the read
A reading below 12.4 volts and your ATV may struggle to crank the engine.
If your battery is low, you can attempt to jump-start from another vehicle or charge your battery with a battery charger.
Battery Load Testing
Checking the voltage is only the first part of checking your battery’s state of health. Your battery will need to be at least 75% charged for this second battery test. So if it’s soft, you’ll need to charge it.
Cranking Battery Test – It is possible for a faulty battery to show a full 12.65 volts. For this test, we’ll connect a DVOM to the ATV and have a helper attempt to crank it over.
If the battery voltage on the DVOM reads below 9.6 volts while cranking for 3-4 seconds, you’ll need to make a trip to the auto store and buy a new battery.
Buying A Battery
Two batteries are common, the traditional wet lead-acid battery or the newer dry glass matt. Either will suit your machine. You can buy online, but the batteries are shipped dry. You’ll need to get the electrolyte locally as they won’t ship it. After you fill it, you’ll need to charge it for about 3-4 hours with a regular charger.
Alternately, do it the old school way – go to a parts store in person and buy a fully assembled charged battery, then it’s plug and play.
Loose or Corroded Terminals
Loose battery terminals are a common cause of no starts. It prevents the proper battery voltage from getting to the starter motor and prevents the stator from charging the battery fully.
Corrosion is a problem too. The traditional wet lead-acid batteries leak as they get older, and the acid causes a crusty white deposit on the terminals. This sets up high resistance in the wiring, and just like loose terminals, it prevents proper starting and charging.
To clean the terminals, use some baking soda and water, but you’ll need to wear glasses and gloves. Acid is nasty.
Remove the terminals, clean with sandpaper, and apply a coat of petroleum jelly after refitting. This helps prevent corrosion.
Faulty Starter Solenoid
The solenoid on most ATVs is a stand-alone component. Others may combine the starter and solenoid and well cover them later.
The function of the starter solenoid is to activate the starter motor. It does this by connecting the battery positive to the starter motor positive terminal when you hit the start button.
Solenoids have internal moving parts and wear out regularly. They commonly offer a click sound when they fail, but not always.
Testing The Solenoid
For this test, the ATV should be in neutral with the brake on.
This is a pretty simple test, disconnect the solenoid control wires. These are the small wires, not the main red power cables.
Using two jumper wires, (power fused) attach one to the positive battery and the other to the negative.
The engine will crank over if the solenoid is good. If the engine doesn’t crank over, your solenoid is probably at fault, but some other possibilities remain:
- Engine ring gear damage
- Starter motor issue
To eliminate these as possibilities, we’ll cross the solenoid poles to test. Warning – As the contacts will arc a little it is not safe to run this test if your battery vent is close to the solenoid, (like the one in the picture) battery vapors are combustible.
Assuming your battery isn’t close to the solenoid. we’ll go ahead and cross the two red heavy cable connectors of the solenoid.
Use a screwdriver with a plastic handle to momentarily connect the poles.
If your engine cranks over, you confirmed a faulty solenoid, go ahead and replace your starter solenoid.
If, on the other hand, the engine doesn’t turn over, go ahead and pull the starter for further inspection.
ATV Starter Motor Testing
ATV starter motors have arguably one of the toughest jobs on an ATV, spinning the motor over fast enough to fire the engine. But these little guys are surprisingly tough. They last for many years without even a thought.
ATV starters come in 3 main flavors, with or without solenoid and with Bendix or without. And finally, a one-way clutch starter motor.
The solenoid you know about, but what’s a Bendix and a one-way thingy ma-jig?
The starter Bendix is an additional feature of a starter motor where the drive gear of the starter motor shoots out to meet and turn the engine’s ring gear. A spring sends it back in after the engine starts. If the Bendix and starter were to stick in the engaged position, the running engine would destroy the starter motor.
The one-way clutch is a common starter type, and it has a clutch system. Its drive gear remains in contact with the ring gear, but a clutch overrides it when the engine starts.
You’ll need to remove it to bench test. A couple of bolts and a power cable usually. With the starter out, check the drive gear for damage and also inspect the engine ring gear, turn over the engine by hand to check the teeth.
Starter on the bench or in a vice, turn the drive gear. It should be smooth and free. Connect a battery and jumper cables as per the diagram.
If it fails to spin, recondition your starter motor.
Faulty Starter Circuit
ATV starter circuits vary from one maker to another and their complexity will depend on what type of safety lock-out systems are used and if the bike is managed by an ECU (computer). A typical ATV starter motor will require the following components in order to activate.
- Battery – the source of all power
- Ignition switch – powered through the main fuse
- Safety lockout switch – on clutch lever or a neutral switch on the transmission
- Start button – usually a ground control
- Solenoid – activated by the start button (ground side)
- Starter – the business end
Safety lock-out – Neutral switch or a clutch switch is typical—the switch, when activated, completes the starter circuit by providing a ground path (usually).
Or the ECU may be signaled when neutral is selected.
If the neutral switch is faulty or wiring damaged, the solenoid won’t have a ground path (or signal) and so won’t engage.
Ignition switch – Obviously plays a big part in the starting sequence. The ignition powers up the dash lights, activates the CDI box.
If the ignition fails to get power to the solenoid, the voltage won’t reach the starter motor.
Start button – It’s a simple on-off switch. Typically when pressed, the start button supplies the starter solenoid with a ground path.
Any fault here will prevent the solenoid from operating.
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John Cunningham is a technical writer here at ATVfixed.com. He’s a Red Seal Qualified Service Technician with over twenty-five years experience. He’s worked on all types of mechanical equipment, from cars and trucks to ATVs and Dirt bikes.