Kawasaki has been making quality utility vehicles for ages, and this Kawasaki Mule review shows how they have improved over the years.
The Mule Pro MX is one of the newest models, coming along just after the Mule Pro FXT debuted in 2015.
The Mule Pro FXT is known to have some common problems, so you’d think these issues would have been corrected in the Mule Pro MX that was introduced a few years later.
Unfortunately for owners, that’s not the case as the Mule Pro MX suffers from seven common problems that drive owners nuts. These include:
- Internal rattling and vibration
- Side doors deteriorating
- Smell of coolant from the exhaust
- Manual lifting of the dump bed
- Engine not starting
- Idling issues
- Loss of speed and acceleration
This guide will detail each problem, what causes it, and proven ways of overcoming each issue.
If you’re considering buying one of these models, I’d highly recommend reading this review of all the good and bad with the Mule Pro MX after reading up on these common problems.
Internal Rattling and Vibration
A number of Mule Pro MX owners have documented a very noticeable rattling and vibration coming from the front of their Mule Pro MX when going at constant speeds of around 14-18 MPH in high gear and around 6-8 MPH in low gear.
Although it tends to happen in many Pro MX models, this occurrence is confirmed as being abnormal by Kawasaki.
This vibration and rattling seems to fade substantially when in four wheel drive, but even then is faintly noticeable.
Fix
The only partial fix for this issue to date is to replace the front propeller shaft connector (Part # 13159-Y002) and the front final drive gear assembly (Part # 13101-Y004).
This will lessen the vibration and rattling to more of just a slight noise, but it is still noticeable.
If you are considering purchasing a Pro MX, it is recommended that you test drive it and check to see if you experience any such vibration or rattling at the speeds listed above.
Side Doors Deteriorating
Though Kawasaki Mule Pro MX models make the list of best UTVs for the money thanks to their high quality parts and components, there is a weak spot in these models.
That weak spot is the plastic side doors, which are known to start to rattle over time and are one of the few Kawasaki Mule accessories included standard on these models.
Additionally, the color inserts on the outside of the doors are simply stick-on decals, and many times start to peel off rather quickly.
Fixes
A simple fix to stop the doors from rattling is to adjust and tighten the nuts and bolts that hold the door in place every so often, which should do the trick.
There’s really no way to stop the color inserts from peeling, so most owners ultimately remove the color inserts altogether when they begin to peel.
Smell Of Coolant But No Leak
One of the more common problems with the Mule Pro MX is the tendency for you to smell coolant (antifreeze) while riding, leading you to think there may be a coolant leak somewhere.
Like many other owners, you’ll go to check your side-by-side from top to bottom, trying to locate this leak with no success.
That’s because some of these models put off the smell of coolant while riding, without there being an actual leak.
The reason for this is not confirmed, but some owners have taken it to the dealer and found that when this happens they have an issue with their head gasket, leading to the coolant smell coming from the exhaust of the vehicle.
Fix
If you’re under warranty still and are having this issue, you’re best off taking your Mule to the dealer to have a look.
There’s a chance Kawasaki will rebuild the engine to fix this (though minimal), or simply replace the head gasket for you.
Manual Lifting of Dump Bed
Although the dump bed in back is a nice feature to be able to dump and unload your cargo, the lift is fully manual.
There is a gas-assist shock in place to ensure that the bed stays upright for you, but it doesn’t assist much with the actual lifting.
If you have more than 100 lbs or so in the bed, you’ll need to be prepared to put some serious muscle into lifting the dump bed in order to unload.
Fix
Kawasaki does offer a hydraulic cargo bed lift that can be installed to assist with heavier lifting, and you can buy one aftermarket as well to alleviate this issue, but be advised that they don’t come cheap.
Engine Not Starting
If you find that your Mule Pro MX’s engine won’t start one day, there are a few common causes of this where you should begin your inspection.
Causes & Fixes
Defective Spark Plugs
If you use your Mule for many short duration trips, such as driving to the mailbox everyday, up and down a path from your dock to your lakehouse, etc., you most likely have a spark plug issue if you find that your engine won’t start one day.
Short duration driving will wear on the spark plugs, so test them and replace them if necessary.
Dead Battery or Loose Battery Cables
Short trips to the mailbox or to the dock can also be hard on your battery, which is where you should look next if the spark plugs aren’t your issue.
Check the battery cables that attach to the battery as well, making sure they’re tightly secured in place.
Transmission Not In Neutral
There’s a safety switch that will prevent the Mule Pro MX’s engine from starting if the vehicle isn’t in Neutral, so if your engine simply makes a clicking noise, make sure the gear shift is firmly in the Neutral setting.
You can sometimes bypass this safety switch on Mule models by pressing down the brake pedal and starting it.
Bad Fuel Pump
If your Mule Pro MX was making a whining sound from near the fuel tank area leading up to the engine not wanting to start, you likely have an issue with your fuel pump.
You’ll need to replace it if it’s not spraying out fuel as it should.
Faulty Ignition Switch
You may also want to test the ignition switch and its voltage to ensure that is not the issue.
Idling Issues
Similar to a common problem found in the Mule SX, the Mule Pro MX is also known to suffer from rough idling and the engine stalling out while at idle.
Many find that the Mule Pro MX runs great while accelerating, but when at idle it will sputter and struggle.
If you run into these idling issues, it’s likely an issue with your Mule’s throttle body.
The throttle bodies in these vehicles have a tendency to become clogged up with gunk and black soot on the inside, leading to these symptoms.
Fix
If you experience them, start with a thorough cleaning of your throttle body to try and get some relief:
- You’ll need to first remove the throttle body from the Mule Pro MX.
- Once removed, spray the inside and outside of the throttle body down with WD-40 Throttle Body Cleaner and scrub it real good using a toothbrush or small scrub brush.
- Be sure to open the throttle blade while you clean to ensure you remove any buildup from the inside area.
- Once clean, reconnect the throttle body to the electrical connections and test it before reinstalling.
- To test, once connected to the electrical connections, simply turn the key to the “on” position and inspect to see if the throttle blade opens slightly.
- If it does, you should be all set and can reinstall the throttle body and fire up your machine.
If this doesn’t fix the idling problems, the fuel filter and/or spark plugs are the next most likely culprits and may need to be replaced.
Loss of Speed and Acceleration
A loss of speed and acceleration in your Mule Pro MX likely signals an issue with a failing fuel pump or a clogged fuel filter, although the spark plugs are sometimes to blame as well.
This exact problem affects the Kawasaki Mule 4010 model, with the loss of speed being most noticeable when going up hills or when carrying a full load in the rear cargo bed.
And this can be quite a bummer for owners, as Mule models are not all that fast to begin with.
Fix
You should inspect the fuel pump to ensure it’s still spraying out fuel as it should be. If not, replacing it may solve your issue.
Before doing that, however, have a look at the fuel filter to see if it appears to be turning the color of dirt, which would indicate clogging.
A clogged fuel filter can eventually cause the drive motor in the fuel pump to fail, which will ruin the fuel pump.
Replace the fuel filter if this appears to be happening. Adding some Sea Foam Motor Treatment to the fuel tank will also help to flush the fuel lines of any dirt and debris that may be contributing to this clogging.
Conclusion:
If planning to buy a used Kawasaki Mule MX, you should be sure to inspect the engine to ensure it starts and idles properly, the brakes to ensure no suspect noises are present indicating potential fixes ahead, and the fluids to ensure everything is fresh.
Additionally, per the rattling problem outlined above experienced in some of these models, it is recommended that you test the Mule MX to ensure that issue is not present before buying.
While some of these common issues are completely out of the owners’ control, others can be alleviated by simply ensuring ongoing proper preventative care and following the suggested maintenance schedule for your Mule.
Regardless of these issues, the Kawasaki Mule MX still makes for an excellent choice if you desire a mid-size UTV that offers a strong mix of workhorse capability and recreational capacity.
See how it stacks up with the Mule Pro FXT Ranch Edition before you go.
