Aragh”, want to ride, I know the feeling, it’s a pain in the ass, but we’ll get it figured out, and you’ll be riding shortly.
The top 5 reasons a dirt bike clicks but won’t start includes:
- Loose battery terminals
- Flat battery
- Faulty battery
- Starter solenoid faulty
- Engine hydro-locked
In this post, you’ll learn about the top 5 reasons your bike clicks and won’t start, how to diagnose it and how to fix it.
1 Loose Battery Terminals
Dirt bikes move about a lot, stating the obvious, right! But the result of all that rough terrain is loose fasteners. And that’s why it’s a good habit to thoroughly inspect your bike regularly. Loose battery terminals will create high resistance, the battery voltage can’t get to the starter motor, and it’s the easiest fix of all.
Locate your battery (usually under the seat) and wiggle the terminals. If they move, they’re loose. Tightening them up will solve the problem. But just before you do, check the terminals for corrosion. Often if the connectors aren’t tight, it will promote arcing and corrosion. Dirty, corroded terminals will also cause resistance.
If you’ve got a white crusty build-up, it’s acid, use gloves and eye protection.
Mix a dessert spoon of baking soda in a cup of water, pour it on the terminals, and allow it 5 minutes to work.
The solution will dissolve the acid. You’ll need to remove the terminals and use some grit paper to clean both terminals and battery posts.
After refitting and tightening fasteners, apply a coat of petroleum jelly, which helps prevent corrosion.
Ok, if this didn’t help we’ll move on and test the battery.
2 Battery Flat
A flat battery is the most common cause of the click sound when your hit the start button. A flat battery doesn’t mean the battery is faulty, but that said, battery failure is common in kit that isn’t used regularly. Batteries love to be recharged regularly and hate laying idle.
A flat battery is a pain, but as bike problems go, it’s a pretty simple fix. Let’s go ahead and check battery voltage.
How to check the battery? You’ll need a DVOM (Digital Volt Ohm Meter) meter and access to the battery.
- Set the meter to 20v dc
- Probe the positive battery post with the red meter lead and the black lead to the negative battery post
Your battery may be flat simply because your bike has been lying idle for an extended period or because of a problem with the charging system (more on this below), or your battery may be faulty (see below).
A battery with 12.5 volts or more should have plenty of power to crank over your engine. However, it is possible for a battery to show a full charge of 12.65 volts and be faulty.
A fast solution to a flat battery is a jump-start also known as a boost start, any 12-volt vehicle can provide a jumpstart, a tractor mower, another bike, car, truck, ATV, etc. So long as both batteries are 12 volts (actually 12.65, but referred to as simply 12 v), they are suitable as a donor battery. The battery voltage is marked on the battery casing.
The jumpstart process is as follows:
Remove in the reverse order: 4, 3, 2, and 1.
3 Faulty Battery
Batteries typically last 3 or 4 years before they fail, sure you can have a battery last longer but you’ll need to store it correctly and use a battery maintainer when in storage, more on this later.
The best way to be sure a battery is up to the job of cranking over your engine is to load test it. You can buy a tool to do this or take the battery to a local parts store, but it’s also possible to use your bike and a DVOM to load test the battery.
However, to load test, we’ll need a fully charged battery. If your battery is below 12.5 volts, go ahead and charge it. See charging your battery below.
Load test your battery
Begin with the battery fully charged or at least 12.5 volts. Set the voltmeter to 20v dc and test as follows:
- Connect the probes as before
- Disable the engine by removing the plug wire (best to ground a disconnected coil)
- Crank the engine for 5-6 seconds and measure the lowest volt reading (set meter to Min-Max)
- A reading below 9.6 volts indicates a failing battery
Charging Your Battery
Batteries that lay idle sulfate and die. Batteries love to be used. The constant charging and discharging of everyday use keep them vibrant. As you know, your bike has a charging system that keeps your bike topped up but only when the engines running.
So when the battery gets low, we need to use an external battery charger. Using a modern smart charger is easy. Connect two crocodile clips, both color-coded red for positive and black for negative. Plug it in, and the rest is automated.
The clever thing about a good-quality smart charger is how versatile they are. They can be used to charge batteries from flat but also to maintain batteries which is crucial, especially on kit that lays idle for long periods. The charger is fully automated. It trickles charges only when needed, so you’ll never hit the start button and hear a click again.
You should know, if your battery gets too low, a battery charger’s safety system won’t allow the charger to turn on. A simple mechanic’s hack – hook up a good battery using booster cables to lift battery voltage and fool the battery charger into turning on.
After twenty minutes, the booster cables can be removed. The total charge time for a battery will depend on the amp rating and how low the battery is. You can budget 3 – 4 hours.
Checking Your Bikes Charging System
Your bike charges the battery automatically. It uses the stator, regulator/rectifier to send a charge to your battery. Testing a bike’s charging system is easy. With the bike running, attach the probes red to the positive battery post and black to negative.
A reading above 13 volts and less than 15.5 indicates a working charging system. If you’re getting readings outside this window you’ll need to test the regulator/rectifier and stator for a fault.
4 Faulty Solenoid
The starter solenoid is a relay that completes the starter circuit when you hit the start button. The relays are a common failure and are known to cause a click sound when they fail. Testing the starter solenoid is easy and we’ll cover that below, but first, we’ll need to locate and identify the starter solenoid.
Locate and identify the solenoid. This is a remote solenoid, most will look like this however, some bikes may have an integrated starter solenoid.
Testing the Starter Solenoid
The solenoid will have two heavy red cables and two light gauge control wires. If you are having trouble finding it, follow the red battery cable from the battery, it leads to the solenoid. The solenoid control wires will be bound together and secured using push-on connectors (usually).
WARNING – Place the bike in neutral as this test involves hot wiring which will bypass lockout switches and ignition systems.
The process is as follows:
- Bike in Neutral
- Disconnect the solenoid control wirs (not heavy red cables)
- Using a positive fused jumper wire, connect battery positive to one solenoid control terminal (doesn’t matter which one)
- Using a negative jumper wire connected ground to the remaining solenoid control terminal. (Touch it briefly to test the solenoid)
What the results mean
Two outcomes are likely, they are:
1 The engine cranked over as normal when I touch the ground jumper wire briefly off the solenoid control terminal – If this sounds like your condition then your solenoid is in great shape, and you may need to go back and check the battery terminals or solenoid terminal connections.
2 The starter just clicks – A weak battery will also cause a starter to click, but if you are happy that you have tested the battery and it’s good then it is very likely your starter solenoid has failed.
There are still some other possibilities but they are less common, but if you want to exhaust all other possibilities no matter how remote, then continue reading.
Fitting a Solenoid
Fitting a solenoid is really simple, it’s a plug-and-play type deal. Here are a few tips to help the job move like butter:
- Disconnect battery negative before beginning (prevent accidental arcing)
- Photograph solenoid before removing
- Remove all wiring and remove the solenoid
- Secure solenoid to body firmly
- Don’t overtighten the solenoid posts (risk craking the solenoid)
- Fit wiring as per picture
- Refit battery negative terminal
You are good to go!
5 Hydro-locked Engine
What is it? It’s when an engine cylinder is filled so full of liquid that the piston can’t move. This condition exhibits very similar symptoms to a flat battery and a faulty solenoid, so taking the extra step when testing might pay off.
It frequently happens to ATVs that venture into the drink without a snorkel. But I know you don’t ride your dirt bike in water, but it doesn’t have to be water. Gas, oil, and coolant are common liquids to find in the cylinder and they will also lock the engine.
So how does it get there? Gas is the most likely liquid to find in the cylinder. Laying the bike on its side can, in some cases, allow oil and gas to fill the cylinder.
A faulty leaking float bowl needle or a float level set too high can cause the gas to keep flowing after shut down.
Not applicable for fuel-injected models.
That’s why using the gas valve (petcock) is always a great idea. Finding coolant inside the cylinder will indicate a cylinder head gasket failure and will require further investigation. It is a far more serious issue.
How to diagnose it and fix it? Remove the spark plug and spin over the engine. Best to disable the ignition coil by disconnecting the control wire. Raw gas and stray spark turn dirt bikes crispy.
Analyze the contents of the cylinder. If it’s gas, you’ll need to look at the carburetor float, as this will happen again. Turning off the gas after shutting down is a short-term solution. If your engine is a four-stroke, you’ll need to change the oil and filter too. Some gas will leak past the rings and into the crankcase, diluting the oil.
Allow the engine to dry out a while and fit a new plug, fire her up and wait for the smoke to clear. No harm done.
Other Causes
I’ve made this shortlist of additional causes, they are less likely but for some, they’ll be applicable:
Too much oil – Sounds too easy right? But overfilling with engine oil is a common occurrence and all that oil needs to go somewhere in order to make room for the crankshaft. If the oil has no place to go then the crank can’t move and we’ll get a click sound.
Similarly, oil that’s too thick and especially in cold weather is hard to move, if the starter and battery can’t manage it, you’ll hear a click.
Faulty starter motor – A failed starter motor is a likely cause of the click sound, that said starters are pretty durable. To test the starter go ahead and remove the spark plug and attempt to crank the motor over, try cranking by hand also using a socket and wrench on the rotor (remove inspection plug). If the engine cranks over by hand, your starter has most likely failed.
Remove the starter and bench test using a battery and jumper wires.
Seized engine – To test for a seized motor, remove the spark plug and attempt to crank the motor as before, try cranking by hand also using a socket and wrench on the rotor (remove inspection plug), if the engine fails to move check the oil level and quality. If the oil is low, it is possible your motor has seized.
You may find these posts helpful:
Start a dirt bike without kickstart
Will bike run without a battery?
How often should I start a bike?
- About the Author
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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.