KYMCO MXU 450i Problems And Their Solutions

Are you tired of encountering issues with your KYMCO MXU 450i? Have you been searching for solutions but haven’t found any reliable resources?

Look no further! In this article, we will explore some common problems that MXU 450i owners face and provide effective solutions to help you get back on the road with confidence.

Whether you’re a seasoned rider or a newbie, this post is for you. So, let’s dive in and discover the solutions to these pesky problems.


8 Common KYMCO MXU 450i Problems And Their Solutions

1. The Engine Won’t Start

The KYMCO MXU 450i experiencing difficulty starting may be attributed to several common issues. One possible problem could be a faulty ignition system, where the spark plug may be fouled, preventing the engine from igniting the fuel-air mixture.

Additionally, a clogged or dirty air filter may restrict the airflow, leading to an insufficient fuel mixture. Fuel system issues, such as a clogged fuel filter or a malfunctioning fuel pump, can also impede the engine’s ability to start.

Lastly, a discharged or faulty battery might hinder the electric starter from cranking the engine. Identifying the specific issue is crucial for an effective resolution.

Solution: To address the starting issues of the KYMCO MXU 450i, follow these steps systematically. Begin by checking the spark plug and replacing it if fouled.

Inspect the air filter for dirt or clogs, and either clean or replace it as needed. Ensure the fuel system is functioning properly by inspecting the fuel filter and fuel pump for any blockages or malfunctions.

If the electric starter is sluggish or unresponsive, examine the battery’s charge and connections, charging or replacing it as necessary. Regular maintenance, including routine checks of these components, can help prevent starting problems and keep the KYMCO MXU 450i running smoothly.

2. Transmission Problem

Transmission problems in the KYMCO MXU 450i can manifest in various ways, such as difficulty shifting gears, slipping gears, or unusual noises during operation.

A common cause of transmission issues is insufficient or contaminated transmission fluid, leading to increased friction and potential damage to internal components.

Additionally, wear and tear on the clutch plates or a misadjusted clutch cable may result in improper engagement, causing slipping and difficulties in power transfer.

If the transmission is not properly lubricated, it can lead to overheating and accelerated wear. Identifying the root cause of these transmission problems is essential for an effective fix.

Solution: To address transmission issues in the KYMCO MXU 450i, start by checking and maintaining the transmission fluid at the recommended level and quality.

Replace or adjust if low or contaminated. Inspect and replace worn or damaged clutch plates, ensuring proper engagement with correctly adjusted clutch cables.

Regularly service the transmission system, including fluid changes, to prevent damage and maintain smooth operation.

If unusual noises or shifting problems persist, seek professional assistance from an ATV mechanic or the manufacturer’s service center for a thorough diagnosis and appropriate adjustments.

3. Fuel Problem

Fuel-related problems in the KYMCO MXU 450i, such as poor engine performance, difficulty starting, or stalling during offroad use, can be attributed to a clogged fuel filter or a malfunctioning fuel pump.

Fuel contamination from dirt or water is also common, compromising the efficiency of the fuel system. Monitoring the fluid level in the fuel tank is essential to identify issues and maintain a consistent fuel supply.

Solution: To address fuel problems, check and replace the clogged fuel filter, ensuring an unobstructed fuel flow. Inspect the fuel pump for proper operation to avoid insufficient fuel delivery, which can cause sputtering or hesitation.

Regularly monitor the fuel tank’s fluid level and consider using a fuel filter with enhanced features for offroad conditions.

This proactive approach helps prevent fuel-related issues and ensures optimal engine performance. Consult a professional mechanic for persistent or complex fuel problems for a thorough inspection and necessary adjustments to the fuel system.

4.  Engine Backfires

Engine backfires on the KYMCO MXU 450i can be indicative of a fuel-related problem, especially during low-speed maneuvers. This low-speed issue may occur due to an incorrect air-fuel mixture, often caused by a lean condition.

The user might experience backfires when trying to start the engine or during deceleration. Aftermarket modifications, such as changes to the exhaust or intake system, can also impact the air-fuel ratio and contribute to backfiring.

Additionally, a clogged fuel injector or a fuel pump with reduced capacity may disrupt the proper combustion process, leading to backfires.

Addressing this problem is essential not only for engine performance but also for the user’s safety and the longevity of critical components like the suspension and brakes.

Solution: To fix engine backfires on the KYMCO MXU 450i, start by ensuring that aftermarket modifications align with the manufacturer’s specifications.

If modifications are causing a lean condition, consider reverting to stock components or adjusting the air-fuel mixture accordingly. Inspect and clean the fuel injectors to address any clogs that may disrupt proper combustion.

Check the fuel pump’s capacity to ensure it delivers an adequate fuel supply. If backfires persist, consult the user manual for recommended settings and adjustments.

Users can remove and clean the air filter, as a dirty filter may contribute to improper air intake and affect the air-fuel ratio.

5. Battery Problem

Battery problems in the KYMCO MXU 450i can lead to difficulties starting the vehicle and may cause the electric starter to fail. Users may encounter a complaint of the vehicle not starting, indicating a potential issue with the battery.

If the battery voltage is too low, the electric system may not function properly, affecting critical components like lights and ignition.

Corrosion or loose linkages on the battery terminals can further exacerbate the problem, disrupting the electrical connection over time.

Troubleshooting these battery-related issues is essential for maintaining the reliability of the KYMCO MXU 450i.

Solution: To resolve battery problems, start by checking the battery voltage using a multimeter. If the voltage is too low, recharge the battery or consider replacing it if it no longer holds a charge.

Inspect the battery terminals for corrosion and clean them with a wire brush to ensure a secure and corrosion-free connection. Tighten any loose linkages to maintain proper electrical contact. Periodically connect the battery to a charger to maintain optimal voltage levels.

If users experience recurring issues, consult the vehicle’s manual for recommended battery specifications and follow the manufacturer’s guidelines for replacement.

6. Leaking Oil

Oil leaks in the KYMCO MXU 450i can be a common concern, and many owners may notice oil spots under the vehicle after use. Worn-out seals or gaskets, particularly around the engine and shift linkage, may lead to oil leaks over time.

The model’s offroad usage and high-speed capabilities may contribute to increased wear on these components, causing oil leaks that can result in a reduced oil level and potential damage to the engine.

Solution: To fix oil leaks on the KYMCO MXU 450i, start by locating the source of the leak. Check for visible signs of oil around the engine, shift linkage, and other critical areas. If worn-out seals or gaskets are identified, replace them with new ones designed for the specific model.

Drain the existing oil and replace it with the recommended oil type and quantity. Tighten any loose bolts or fasteners contributing to the leaks.

Regularly inspect the vehicle for oil leaks and address them promptly to prevent long-term damage.

7. Noise Problem

A common issue experienced by KYMCO MXU 450i owners is an unusual noise coming from the machine during rides. Many riders may notice a distinct sound, especially at higher speeds or during acceleration.

This noise problem could be attributed to a misaligned or worn-out drive belt. Over time, the belt may experience wear and tear due to high-speed operation, causing it to produce undesirable sounds.

Riders may also encounter noise issues when shifting gears, and a misaligned or malfunctioning shifter may contribute to this problem.

Regular offroad usage and high-speed riding conditions may exacerbate these noise concerns, prompting the need for a timely solution to maintain the optimal performance of the KYMCO MXU 450i.

Solution: To address the noise problem in the KYMCO MXU 450i, start by inspecting the drive belt for signs of wear, misalignment, or damage.

Replace the belt with a high-quality, manufacturer-recommended replacement if necessary. Check the shifter for proper alignment and functionality, ensuring smooth and precise gear changes.

Tighten any loose bolts or fasteners in the drive belt system that may contribute to noise. Perform regular maintenance, including belt inspections, from time to time, to catch potential issues early.

If the noise persists, consult the user manual for recommended RPM levels and adjust the machine’s speed accordingly, as excessive RPM may also lead to noise problems.

8. Faulty Camshaft

The KYMCO MXU 450i may experience performance issues due to a faulty camshaft, leading to poor engine performance and potential damage. Wear, exposure to extreme conditions, and debris entry can contribute to camshaft problems, affecting overall engine functionality.

Solution: To address a faulty camshaft, inspect for wear, damage, or debris. Replace the camshaft with an approved part, and check related components like the timing chain.

Regularly inspect and clean the air filter to prevent debris entry. Avoid extreme operating conditions. Seek professional assistance for a comprehensive diagnosis and resolution.

Frequently Asked Questions

What motor is in the Kymco 450i?

The Kymco MXU 450i is powered by a 443cc, SOHC, liquid-cooled, single-cylinder engine.

What is the towing capacity of the Kymco 450i?

The Kymco MXU 450i has a towing capacity of approximately 1,050 pounds.

Are KYMCO quads any good?

Yes, KYMCO quads are generally considered good, offering reliable performance and durability.


The KYMCO MXU 450i, a mid-sized utility vehicle with great features, provides consumers with a reliable offroad experience.

Addressing common issues such as fuel-related problems, transmission concerns, and battery issues promptly ensures the vehicle’s maximum performance.

With a towing capacity of around 1,050 pounds and a top speed of approximately 50 mph, the KYMCO MXU 450i offers a versatile and durable option for various offroad activities.

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