6 Common KYMCO MXU 450i Problems (With Fixes)

The KYMCO MXU 450i is a mid-sized UTV with many great features. These include a steel front bumper, a 4-wheel suspension, and a sealed air intake filter. But there are a few issues with the UTV you should know about.

The most common KYMCO MXU 450i problems are oil leaking, gas leaking from the injector, gear getting stuck, low speed, colliding noise, and faulty camshaft.

But if you follow the procedures given below, these problems are simple to resolve. The issues listed above will be covered in this article.

KYMCO MXU 450i Problems

KYMCO MXU 450i Problems

Users of the KYMCO MXU 450i frequently complain about various issues. 

Here are some of them along with their solutions.

1. Leaking Oil

According to consumers, there are a variety of reasons why a UTV like the KYMCO MXU 450i could experience oil leaks.

Oil seals that are worn out and defective gaskets are the main reasons. 

Other frequent causes for the problem include cracked oil pans, loosened oil drain plugs, or broken oil lines.

Oil marks under the UTV and a low oil level are two typical signs of an oil leak. 

You may get a whiff of burnt oil or hear odd engine noises if you pay close attention.


Follow these steps to remedy an oil leak in a KYMCO MXU 450i:

  1. Discover the leak’s origin.
  2. Check the UTV carefully for any indications of an oil leak. 
  3. Drain the oil.
  4. Remove the gasket or oil seal if that is what is causing the leak.
  5. Replace it now with a fresh one.
  6. Before fitting the replacement gasket, make sure to give the region a thorough cleaning.
  7. The oil pan must be replaced if it is fractured.
  8. In some circumstances, you might be able to weld or use epoxy to fix the oil pan.

2. Injector Leaking Gas

Your KYMCO MXU 450i UTV’s fuel injector leak could make it impossible for the engine to start or make it run poorly. 

Hard starting and poor idle are typical signs of an injector leak. 

There are a number of potential causes for a fuel injector leak, including clogged injectors or damaged O-rings. 

This problem can also be brought on by frayed fuel lines or a malfunctioning fuel pressure regulator.


Locate the fuel injector on your UTV’s engine, then disconnect the battery. Remove the fuel injector from the engine. 

Examine the O-rings and fuel injector for any evidence of damage.

Replace the O-rings if they are harmed. To clean the injector, use a fuel injector cleaner. Eliminate any buildup or debris. 

By connecting the two fuel lines, reinstall the fuel injector into the engine. Set the bolts into position.

If the fuel injector is still leaking, the issue may be with the fuel pressure regulator or the fuel lines themselves. 

The regulator or fuel lines may need to be replaced in this situation.

3. Gear Gets Stuck

Owners of the KYMCO MXU 450i made complaints about this trouble. Your UTV’s gears may be stuck for one of the following reasons:

  • Defective shift lever
  • Broken shift forks
  • Low transmission fluid
  • Defective clutch

The signs include:

  • Having trouble changing gears.
  • Gear getting stuck indefinitely.
  • Shifting with a crunching sound.
  • Uncommon clutch performance.


Look for wear on the shift lever. Verify that the shift lever is not misaligned or loose. Examine the shift forks for any damage indications. 

The shift forks must be replaced if they are damaged.

Check the transmission fluid’s level and state. Fill it properly if the fluid level is low. Make sure the shift linkage is properly aligned by adjusting it. 

While the engine is off, test the gears by shifting through each gear.

4. Low Speed

This issue is present with some KYMCO MXU 450i due to a manufacturing fault. 

If the restrictor plate in the throttle body has not been removed, it reduces the speed.

As a result, the UTV will have a maximum revolution of 6000 RPM. The top speed is limited to approximately 45 mph.

The throttle movement may be limited to about an inch and a half. As a result, power output will be reduced by about 40%.


Locate the throttle body by removing the airbox lid. Bolts are used to secure the restrictor plate in place.

The restrictor plate can be taken off with pliers. When removing the restrictor plate, take care not to harm the throttle body or other parts.

Put the throttle body back together after the restrictor plate has been taken off.

5. Colliding Noise 

You might hear the KYMCO MXU 450i making an unusual noise. 

After closer examination, the users discovered that the crankshaft and flywheel were the sources of the noise.

A worn-out or damaged clutch bearing is to blame for this. It is also typical for damaged clutch bearings to put stress on the main bearings.


Follow these steps to resolve the issue:

  • Remove the engine and disconnect the battery.
  • Utilizing a flywheel puller, detach the flywheel from the crankshaft.
  • For signs of excessive wear, examine the crankshaft bearings. 
  • Keep an eye out for any trash or metal shavings that might point to a major issue.
  • Look for any wear or damage on the clutch bearing.
  • Replace the clutch bearing if it is damaged.

6. Faulty Camshaft 

Camshaft problems are a frequent complaint among KYMCO MXU 450i owners. 

This issue may be brought on by camshaft wear or damage as well as inadequate lubrication.

Signs of this problem include:

  • Engine efficiency decreasing
  • Engine stalling
  • Engine making noise
  • Fuel efficiency declining


From the engine, remove the camshaft. Examine the camshaft for evidence of damage. This includes lobes that are flat or damaged.

It will be necessary to replace the camshaft if it is damaged. Examine the pushrods and valve lifters. 

Replace any broken parts.

Tips for Buying a Used KYMCO MXU 450i

Before you decide to purchase a used KYMCO MXU 450i UTV, you need to adhere to a few standard measures. 

First of all, inspect if the injector is leaking gas. If the old UTV leaks gas, it will also be hard to start.

Oil leaking is also common with old KYMCO MXU 450i. Inspect the underneath of the UTV to ensure that there are no leaks.

If you notice noise coming from the crankshaft and flywheel, the crankshaft bearing might be damaged. So, avoid the ones with this kind of noise.

If the camshaft has a flat lobe, the engine will stall. You might want to hire a professional to inspect this issue. 

Also, make sure that the restrictor plate has been detached.


What type of engine is used on the KYMCO MXU 450i?

443cc SOHC engine with liquid cooling.

How much is the towing capacity of the KYMCO MXU 450i?

1050 lbs.

What type of transmission is provided with the KYMCO MXU 450i?

CVT automatic transmission.

How much is the horsepower on the KYMCO MXU 450i?


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