10 Most Common Kawasaki MULE SX Problems and How to Fix Them

An upgrade to the MULE 680, the MULE SX boasts a tilting steel bed with a 400-pound weight limit, a tilting steering wheel, and a rectangular cargo guard with a more functional design than its predecessor. Top it off with a MacPherson-strut suspension for the front wheels and a swing-axle rear suspension, and you have a UTV that can handle anything you throw at it.

Despite the largely positive reviews, the Kawasaki MULE SX has its drawbacks. The most common Kawasaki MULE SX problems are ignition issues, Gear shift problems, squealing brakes, abrupt speed reduction/acceleration, oil filter cap popping off, oil leaks, sputtering and stalling, electrical issues, power loss, and strange rattling noises.

Are you planning to purchase a Kawasaki MULE SX? Learn potential issues you’ll encounter and how to deal with them.

Problems With the Ignition

Many MULE SX owners have complained about ignition issues. However, this problem isn’t unique to this particular UTV. Most utility vehicles encounter problems with the ignition with continued use. Try the following fixes if your MULE SX fails to start.

Check Your Battery and Fuel Level

A dead battery won’t produce the spark needed to start your UTV. Use a voltmeter to check whether the battery still has juice. If the battery is dead, revive it with a high-quality battery charger.

Also, top up the fuel if the tank is empty and see if it solves the problem. If neither works, you likely have a problem with the fuel pump. A licensed mechanic will help your repair or replace the pump.

Check the Neutral Safety Switch

If you turn the key and hear a clicking sound, you probably have the neutral safety switch on. This switch keeps the UTV from starting when in gear and prevents accidents by cutting power to the starter.

A faulty neutral switch will cut power to the starter even when the UTV isn’t in gear. Simply step on the brake pedal to bypass the faulty switch, and your UTV will come to life. Consider replacing the neutral safety switch if the problem persists.

If the above fixes don’t work, you likely have a malfunctioned fuel ignition module. Try opening it up and checking the ignition coil and spark plugs for damage. Replace the damaged parts to solve ignition issues permanently.

Gear Shifting Problems

Kawasaki MULE shifting problems are annoying and severely compromise your driving experience. Shifting from one gear to another is sometimes difficult with the MULE SX. The issue largely concerns Kawasaki’s gear design, opting for a collar shift transmission.

With a collar shift transmission, gears must line up with their respective collars or the gear jams. Sometimes the collars match up with others, leaving the stick shift stuck. If this happens, hit the gas to engage the clutch, which will position the gear correctly.

Squealing Brakes

Unfortunately, the brake pads on the Kawasaki MULE SX don’t last as long as most owners want them to. 

Squealing brakes are among the most annoying Kawasaki MULE SX problems, indicating that the brakes are worn out and need replacement. Replacing the brake pads will stop the squealing and improve the brakes’ functionality.

Abrupt Reduction in Speed and Acceleration

Picture riding your Kawasaki MULE SX around your farm when it suddenly slows down and accelerates abnormally. This is a reality for most MULE SX owners, who have often experienced this issue.

Acceleration problems usually result from a faulty fuel pump or a clogged fuel filter. Check the filter and replace it if clogged. If that’s not it, replace the fuel pump with a new one for a permanent fix.

Oil Filler Cap Popping Off

The oil cap, as the name implies, is the cap that sits on top of the engine valve cover to prevent oil from spilling out of the engine.

Sometimes gas from the exhaust can create moisture which freezes when temperatures drop. The ice formed clogs the breather tube, creating a pressure buildup that pops off the oil filler cap.

Unfortunately, this is a problem you’ll have to live with. Your best bet is to screw on the cap again and hope the fuel catch will catch the spillage.

Leaking Oil

The oil catch in your MULE SX is incredibly useful for catching oil spills when the filler oil cap comes off. Below this catch is a drain pipe for draining the oil that the oil catch collects. Sometimes this pipe gets filled up and starts to overflow, causing oil leaks.

You can avoid this issue by draining the spilled oil before the drained pipe fills up. The manual has clear instructions for doing just that. Regularly check the drain plug and drain it whenever necessary.

Engine Sputtering and Stalling When Idle

Some Kawasaki MULE SX owners have complained of engine problems, including sputtering/stalling whenever the UTV idles. 

This is likely because the throttle body is dirty from excessive soot buildup. Cleaning the inside of the throttle body should solve the issue. Here’s how you do so:

  • Carefully remove the throttle body
  • Use a high-pressure cleaner to spray the inside of the throttle body and brush it clean with a nylon brush
  • Use your finger to open the throttle blade and spray the cleaner inside to clean it
  • Hook up the electrical connections to the throttle body and turn the key to see if the blade opens
  • Reinstall the throttle body, and you should have no issues with engine sputter and stalling when you idle your UTV. If you’re not confident about opening up and connecting the throttle body, you can get professional help

Electrical Complications

Problems with electrical components in your Kawasaki MULE SX are brought about by faulty wiring or a dead battery. Jump-starting the UTV should solve the latter. Wiring issues are a tad more complicated.

A plastic burning smell usually indicates issues with your UTV’s wiring. Wiring issues are incredibly complicated and dangerous to fix. Call your local mechanic to check the wiring and make necessary repairs.

Sometimes, you might have to replace a few electrical components. You should leave Kawasaki MULE SX problems like wiring and replacing electrical components to the pros.

Strange Rattling Noises

Rattling noises from your Kawasaki MULE SX UTV indicate loose parts you need to secure. Turn the engine on and listen carefully to establish the cause of the rattling. In most cases, the rattling is in the clutch. And while not harmful, the rattling can get pretty annoying.

Unfortunately, this is a design flaw with the Kawasaki MULE SX; you’ll just have to live with the noise. You probably have a loose part if you notice rattling noise that doesn’t come from the clutch. Secure any loose parts with a spanner, and you’re good to go.

Power Loss

Power loss issues are common with aged Kawasaki UTVs, and the MULE SX is no exception. This problem is more apparent when driving your UTV in hilly places.

The problem typically stems from a malfunctioning fuel pump or clogged fuel lines. Replacing these parts should restore normal functioning.

Are Positive Kawasaki MULE SX Reviews False?

Reading through these Kawasaki MULE SX problems, it’s easy to think that the positive reviews are misleading. However, most of the above issues are standard with UTVs and aren’t necessarily deal breakers.

You could easily fix the above issues and get your UTV back to tip-top form. The more you take good care of your Kawasaki MULE SX, the more you get the most out of it. Get help from a licensed mechanic if any of the above problems get out of hand.