Dirt Bike Clicks But Won’t Start (Success)


Aragh”, just 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:

  1. Loose battery terminals
  2. Flat battery
  3. Faulty battery
  4. Starter solenoid faulty
  5. Engine hydro-locked

In this post you’ll learn about the top 5 reasons your bike clicks and wont start, how to diagnose it and how to fix it.

Loose Battery Terminals

Dirt bikes move about, a lot, stating the obvious, right! But the results of all that rough terrain is loose fasteners. And that’s why it’s a good habit to thoroughly inspect your bike regularly.

Loosed battery terminals will create high resistance, the battery voltage simply can’t get to the stater motor, and it’s the easiest fix of all.

Locate your battery (usually under 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, so use gloves and eye protection. Mix a desert 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 using some grit paper clean, both terminals and battery posts.

After refitting and tightening fasteners, apply a coat of petroleum jelly, helps prevent corrosion.

Battery Flat

A flat battery is the most common cause of the click sound when your hit the start button. Sure, it’s a pain, but as bike problems go, it’s a pretty simple fix

How to check the battery? You’ll need a DVOM (Digital Volt Ohm Meter) meter and access to the battery.

  1. Set the meter to 20v dc
  2. Probe the positive battery post with the red meter lead and the black lead to the negative battery post

Check your readings against the following:

  • 12.65 volts 100% charged
  • 12.4 volts 75% charged
  • 12.2 volts 50% charged
  • 12.0 volts 25% charged
  • 11.9 volts discharged (Flat)

Your battery may be flat simply because your bikes been laying idle for an extended period or because of a problem with the charging system (more on this below) of faulty battery.

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.

Faulty Battery

The only way to be sure a battery is up to the job, 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, before we can do the 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 volt meter to 20v dc

  1. Connect the probes as before
  2. Disable the engine by removing the plug wire and grounding
  3. Crank the engine for 5-6 seconds and measure the lowest volt reading
  4. A reading below 9.6 volts indicates a failing battery

Charging Your Battery

Batteries that lay idle sulphate and die. Batteries love to be used, the constant charging and discharging of everyday use keeps them vibrant.

As you know, your bike has its own 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 colour 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 lay idle for long periods.

The charger is fully automated, it trickle 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 chargers safety system won’t allow the charger turn on.

A simple mechanics hack for his is to 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 ca be removed, 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 bikes charging system is easy, with the bike running, attach the probes red to positive battery post and black to negative.

A reading above 13 volts indicates a working charging system.

If you’re getting readings below 12.65 volts, you’ll need to test the regulator/rectifier and stator for a fault.

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 click sound.

Testing the starter solenoid is easy, first identify the solenoid, it will have two heavy red cables and two control wires. The control wires will be bound together and fitted with a connector.

Place the bike in neutral as this test involves cranking the engine over.

Test as follows:

  1. Follow the loom from the solenoid and disconnect the solenoid
  2. Using a jumper wire, connect battery positive and either of the two control wires.
  3. Using a second jumper wire connected to the second control wire, touch it briefly to chassis ground. If the engine cranks over the solenoid isn’t at fault.
  4. If the solenoid still clicks, go ahead and remove the spark plug and wrap the coil wire in a shop towel. Again, touch the ground wire to chassis briefly. If the solenoid still clicks, it’s faulty and needs to be replaced.

Doing part four of this test is necessary as a condition known as hydro-locking can also cause the engine to click. (see below)

Hydro-locked Engine

What is it? Its when an engine cylinder is filled so full with liquid, that the piston can’t move. This condition has 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 ATV’s 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 too.

So how do they get there? Gas is the most likely liquid to find in the cylinder. Laying the bike on it’s side can in some cases, allow oil and gas 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, that’s why using the gas valve is always a great idea.

Coolant inside the cylinder will indicate a cylinder head gasket failure and will require further investigation.

How to diagnose it and fix it? Remove the spark plug and spin over the engine. Wrap the plug wire in a shop towel, gas and stray spark turns dirt bikes crispy.

Analyse the contents of the cylinder, if it’s gas, you’ll need to take a look at the carburettor float, as this will happen again. Turning off the gas after shut 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 dry out a while and fit a new plug, fire her up and wait for the smoke to clear. No harm done.

John Cunningham

John Cunningham is an certified mechanic and writer on ATVFixed.com. I’ve been a mechanic for over twenty years, I use my knowledge and experience to write articles that help fellow gear-heads with all aspects of ATV ownership, from maintenance, repair to troubleshooting.

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