A flat battery is a common everyday issue and easy to solve, you jumpstart her, right? But what do you do if even jumpstarting doesn’t solve the problem? Well, you are in the right place, I’m a mechanic and very shortly we’ll have it figured out.
Four common reasons an ATV won’t jumpstart, include:
- Loose battery terminals
- Wrong jumpstarting sequence
- Faulty starter solenoid
- Faulty neutral switch
In this post, we’ll cover all the common reasons your ATV won’t start, how to diagnose them and what you can do to fix them right now!
Pre Diagnosis Checks
Before we get into the actual diagnosis of the no start let’s first check we’re on the same page. To do that we’ll need to know what noise your engine makes when you attempt to jumpstart. The answer to this question will help determine what the likely cause is and therefore help get you back rolling quickly.
When jumpstarting and you hit the start button, commonly you’ll hear one of four sounds. Check out the links below that corresponds with what sound your ATV makes (if any) when you hit the start button.
The four likely sounds are:
- Repeated clicking sound
- Single click sound
- No sound at all
- The engine just cranks over, but doesn’t start (this is a biggie and I’ve covered it previously. You can check that out here – ATV won’t start)
Loose/Dirty ATV Battery Terminals
I’ve put this at the top of our list because it’s common and a one-minute fix, you’ll likely spend longer looking for the wrench than fixing the problem.
ATVs bounce about a lot and so it’s no surprise a few fasteners come loose from time to time. Of course, we should check the battery terminal fasteners are tight during maintenance checks, but given their location, they’re forgotten.
Anyhow, loose terminals create resistance to the flow of voltage both from the battery but also to the battery meaning your battery power can’t get to the starter motor, and nor can the charging system get voltage to the battery.
Diagnose: Access the battery and move the terminals from side to side, if they move they will create high resistance.
Fix: Use an adjustable wrench to snug them up, but not too tight, these guys can break if over tightened.
Dirty Battery Terminals
Dirty terminals will also cause resistance issues and is another common cause of hard starting. Corrosion can be seen as a white crusty buildup on the terminal itself. This is acid and will burn the skin, so use caution.
Diagnose White crusty buildup on the battery terminals.
Fix: Clean terminals but first neutralize the acid by mixing baking soda and some water into a paste and applying to the corrosion. After a few minutes, you are free to remove the terminal, clean it with sandpaper or wire brush snd refit, taking to tighten it securely.
Apply some petroleum jelly to help guard against future corrosion.
Wrong ATV Jumpstarting Sequence
Jumpstarting isn’t difficult, but sometimes when attempting to jumpstart in difficult conditions, terrain, or maybe in poor light, cables can get mixed up. Best to take a moment to check that the jumper cables are connected correctly.
Connect the cables in the following order:
- ATV battery Positive (+)
- Donor battery Positive (+)
- Donor battery negative (-)
- Ground point
You may use any 12-volt battery, or donor vehicle such as Car, Truck, Tractor mower, RV, etc. I’ve covered jumpstarting an ATV previously in greater detail and you can check that post out right here – How to jumpstart an ATV in 6 easy steps
A very common root cause of unsuccessful jumpstarting is not the fitting sequence but the cables themselves. Yep, bad quality or faulty cables are a pain because they lead you to believe you have a different problem. I’ve been caught once burning time because of faulty cables.
Anyhow make sure your cables are up to the job, weak crocodile clamps or frayed wires at the clamps are where they usually fail. I’ve listed a good-quality jumper set and a jump pack on the ATV tools page here.
Faulty ATV Starter Solenoid
The starter solenoid is a relay, it connects the battery to the starter motor when but only when the relay is activated by the start button. Solenoids work hard and fail regularly, a common tell-tale symptom is a single click sound when the water button is pressed.
That said a single click sound may be caused by some faults too low battery (although more often, a low battery offers several repeated clicks); valve lash out of spec; hydro locked engine; engine failure.
We’ll eliminate all of these as possibilities by checking the solenoid starter solenoid. After all it is the most likely reason we hear the departed clicking sound. However, if our solenoid tests is good, you’ll need to visit all these other possibilities just mentioned.
Testing the starter solenoid
To test the starter solenoid we’ll need two lengths of electrical wire one fuesed. In this test we’ll bypass the start switch and the ignition switch. The bike should be in neutral and parking brake applied, we’ll be cranking over the engine and if it’s in gear it will move. Testa as follows:
First locate the starter solenoid, usually close to the battery.
Access the two light gauge wires and remove them.
Using two jumper wires, (power fused) attach one to the positive battery and the other to the negative (as per picture).
Two outcomes are possible:
Your engine doesn’t crank over, it just clicks once. Most likely your starter solenoid has failed, as said they fail regurarly, and I’d just go ahead and replace it. That said there are a couple of other possible causes (less likely) and in the interest of a complete diagnosis you can check those out here in this post – ATV will only pull start
Engine crank over as normal – That’s great! But it means you’ll need to check out your safety lock-out system (neutral switch clutch switch etc,) or kill switch. Check out – ATV will only pull start, it covers the subject in more detail.
Faulty ATV Neutral Switch
A common cause of no sound at all when the start button is pressed is the Kill switch, worth taking a moment to check it’s in the RUN position. Hey, it happens.
However, for most, the more likely issue is a more technical issue such as a faulty lock-out system wiring or sensor issue. A transmission neutral switch is the most common sensor or switch used to prevent unintended in gear starts, but some may use a clutch lever too.
As you know the neutral light must be on in order for the starter to engage. If your light isn’t lit your bike’s CDI or ECU assumes the bike is in gear and won’t send power to the starter motor.
While obviously starting circuits vary from maker to maker but even the simplest ATV wiring circuits will incorporate a safety lock-out feature or maybe two.
I wrote an article on checking neutral light issues and you can check it out here – Neutral light always on
Other Possible Causes
Here you’ll find some other less likely but still possible causes of a no crank when attempting a jumpstart.
- Faulty starter motor – ATV will only pull start
- Hydro locked engine – ATV won’t start
- Engine flooded – ATV flooded with gas
- Faulty CDI/ECU
- Wiring issue
- Mechanical fault – ATV has spark and fuel but won’t start
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