Common CFMoto 500 Problems & How to Fix Them

Having issues with your CFMoto 500 ATV? You’re not alone. As a popular entry-level sport ATV, the CFMoto 500 is bound to have some common problems pop up from time to time. In this detailed troubleshooting guide, we’ll cover the most frequent CFMoto 500 problems owners face and provide fixes to get you back on the trails.

From engine troubles to suspension woes and electrical gremlins, many CFMoto 500 problems can be solved in your garage with some basic mechanical knowledge and the right approach. Read on as we dive into real-world troubleshooting and repairs for the CFMoto 500.

What Are the Most Common Problems on the CFMoto 500 ATV?

The CFMoto 500 burst onto the scene around 2009 as an agile sport quad with smooth power delivery from its 493cc liquid-cooled single cylinder engine. With nearly 40 horsepower on tap, it had plenty of pep for recreational trail and dune riding.

As a budget-oriented Chinese ATV, CFMoto cut some corners in component quality but overall build quality has proven decent if properly maintained. So what problems plague the 500 most often?

Overall, the top issues reported by CFMoto 500 owners are:

• Engine surging, sputtering or loss of power – caused by dirty air filters, clogged fuel injectors, failing fuel pumps or sensors
• Overheating – from coolant leaks, stuck thermostats, or faulty water pumps impeding flow
• Transmission problems like hard shifts and slipping gears due to worn shift components and gear teeth
• Suspension issues like bottoming out and loose handling from underdamped shocks and worn swingarm bearings
• Electrical failures stemming from loose battery connections, bad stators, and flakey solenoids or switches

While not exactly bulletproof, many CFMoto 500 problems can be prevented with routine maintenance and inspected early before causing breakdowns. Let’s explore the most common issues in detail and how to get your quad running right again.

Frequent CFMoto 500 Engine Problems and Repairs

Without a properly running engine, your quad won’t get far. Engine issues account for a large portion of CFMoto 500 problems reported by owners. Here are the most frequent engine-related issues and how to diagnose and fix them:

Engine Surging, Sputtering or Losing Power

One of the most common complaints on the CFMoto 500 quad is the engine running erratically, surging unexpectedly, or losing power. There are a few common culprits:

• Clogged Air Filter – The air filter keeps debris out of the engine but gets dirty over time. If caked in dirt, it restricts airflow causing poor running. Check the air box and replace the filter every 20-30 hours. Use OEM or high quality aftermarket filters to prevent premature failure.
• Dirty Fuel Injectors – The 500 uses a single fuel injector to spray gas into the cylinder. Over time, deposits inside the injector nozzle can impede the spray pattern. Use a fuel injector cleaner regularly to prevent this. For heavy buildup, injectors may need professional cleaning or replacement.
• Fuel Delivery Issues – Weak fuel pressure due to a failing fuel pump or clogged fuel filter can cause engine stumbling and power loss. Check fuel pressure at the rail. It should be 350 kPa. A new pump may be needed if pressure is low despite changing the filter. The fuel pressure regulator can also fail causing symptoms.
• Faulty Sensors – The crank position sensor, cam position sensor, intake air temp sensor, and oxygen sensor help the ECU control fueling. If any fail, it can cause erratic running. Check sensors and replace any faulty ones.

By methodically inspecting the air filter, injectors, fuel delivery system, and sensors, you can isolate what’s causing poor engine performance on your CFMoto 500.

Overheating Problems

The liquid-cooled 493cc thumper relies on the cooling system to maintain proper operating temperature. CFMoto 500’s prone to overheating usually have an underlying issue impeding coolant flow or heat dissipation:

• Low Coolant – That plastic overflow bottle is there for a reason – to top off coolant lost through leaks or evaporation. Periodically check levels and top up when low. Use a 50/50 mix of coolant and distilled water.
• Clogged Radiator – Mud and debris easily gets stuck in the radiator fins. Use compressed air or a garden hose on gentle spray to blow out the radiator and allow maximum airflow. Inspect fans for any damage too.
• Faulty Thermostat – A stuck closed thermostat prevents coolant flow to the radiator. Replace the thermostat with an OEM equivalent if it’s not opening fully when the engine is hot.
• Bad Water Pump – Coolant needs to circulate when the engine is running. A faulty water pump impeller shaft or leaky pump seals can diminish flow resulting in overheating. Test pump operation and pressure output. Rebuild or replace as needed.
• Head Gasket Failure – Extreme overheating can cause a blown head gasket allowing coolant and oil to mix. White exhaust smoke, coolant leaks, and oil contamination point to a blown head gasket. The head gasket must be replaced if so.

While not the most fun DIY project, thoroughly inspecting the cooling system components and making necessary repairs will get to the bottom of overheating issues. Don’t overlook simple things like dirt buildup that can lead to big problems later.

Diagnosing Common CFMoto 500 Transmission Problems

Now that we’ve covered some frequent engine issues, let’s move on to common problems with the CFMoto 500’s manual transmission. Here’s what to watch out for:

Hard Shifting Between Gears

Does your CFMoto 500 give you a hard time when trying to shift? Difficult shifting could stem from:

• Clutch Cable Adjustment – The clutch cable needs a few millimeters of free play at the lever. If too tight or loose, it will cause incomplete clutch disengagement and rough shifting. Adjust cable free play to spec in your repair manual.
• Low Transmission Fluid – Ensure proper fluid level first. If low, top up with the specified grade in your owner’s manual. Change fluid regularly as old fluid loses its lubricating properties.
• Worn Shift Forks – The shift forks move gears on the shafts during shifts. Excess play causes sluggish engagements. Inspect and replace bent or heavily worn shift forks.
• Sticking Shift Drum – The shift drum positions the forks for gear changes. Gunk buildup causes sticky operation. Clean and grease the shift drum assembly.

Methodically inspecting the clutch, fluid, shift forks and drum should reveal the culprit of hard shifting. Parts replacement and proper lubrication will get your CFMoto 500 shifting smoothly again.

Transmission Slipping Out of Gear

Does the transmission slip when accelerating or climb out of gear entirely? Here are some likely causes:

• Worn Shift Drum – As mentioned above, the shift drum positions gears during shifts. Excess play from wear allows gears to disengage under load. Inspect the shift drum teeth for wear or damage. Replace the drum if evident.
• Bent Shift Forks – Worn or bent shift forks can also allow gears to pop out under acceleration. Check fork engagement in each gear and replace any bent parts.
• Broken Shift Shaft – The shift shaft turns the shift drum via shift pedal input. A broken shaft means no shifting ability. Assess the shaft condition and replace if damaged.

Checking these key components inside the transmission will reveal why your CFMoto is popping out of gear. Then the worn parts can be replaced and any debris cleaned out to improve shifting performance.

How to Fix Common CFMoto 500 Suspension Problems?

Now let’s move on to the chassis and suspension. ATVs take a lot of abuse from rough terrain, so expect some suspension issues over time:

Bottoming Out Suspension

Bottoming out over big bumps and g-outs? A few things can contribute to that harsh jolt:

• Soft Springs – If the shock springs feel too soft, they likely are. Stiffer replacement springs will prevent bottoming and allow full travel over jumps. Work within your riding style and weight.
• Not Enough Preload – Preload adjustment compresses the shocks to limit down travel. Dial in more preload until bottoming stops. Too much preload decreases plushness and control though.
• Worn Out Shocks – Eventually shocks lose their damping ability. Frequent bottom out or oil leaks point to shot shocks. Upgrade to better aftermarket shocks for improved damping and bottoming resistance.
• Low Tire Pressure – Don’t overlook something simple like tire pressure. Low pressure allows the sidewalls to roll over easier contributing to bottom outs. Inflate to the recommended PSI for your tires.

Make bottoming out a thing of the past by adjusting preload, replacing weak springs or worn shocks, and minding your tire pressure.

Loose, Wobbly Handling

Do you feel like the front end wanders or chassis feels flexy in corners? Possible causes include:

• Steering Stem Bearings – The steering stem bearings need to be snug with no play. If loose, tighten them to spec or replace if worn out or pitted races are evident.
• Worn Swingarm Bearings – Play in the swingarm pivots allows the rear to sway. Inspect bearings for slop or roughness and replace if necessary.
• Soft Sway Bar – An aftermarket sway bar tightens up chassis roll. Choose a bar rate ideal for your riding style and skill level.

Don’t put up with a loose front end or vague handling any longer. Ensure steering stem and swingarm pivots are tight with no play, and upgrade the sway bar for more precise cornering.

Tracking Down Common CFMoto 500 Electrical Problems

Electrical issues can certainly be frustrating. Let’s outline the most frequent electrical problems on the 500:

Battery Issues

Electrical components rely on consistent voltage from the battery. Two things commonly plague the battery:

• Loose Connections – Vibration can loosen the battery terminals over time. Remove any corrosion with a wire brush and re-tighten connections firmly for a solid contact.
• Dead Cell – If the battery shows good voltage but still struggles cranking the engine, a dead cell is likely preventing full output. Load test the battery and replace it if faulty.

Check those basic connections first before assuming the battery is bad. Clean terminals and ensure a tight fit.

Faulty Starter System

When you hit the magic button but nothing happens, the starter system should be inspected:

• Bad Starter Solenoid – The starter solenoid acts as the switch interface between the ignition and starter motor. If it’s not closing properly, the starter won’t crank. Test solenoid function and replace it if faulty.
• Brushes Worn – The starter motor uses copper brushes to transmit current to the armature. After years of use, they wear out. Inspect starter brushes and replace if under 3/8″ long.
• Damaged Starter – Faults inside the starter motor like worn bushings, debris, or burnt windings can also prevent cranking. Try rebuilding or replace it if diagnosed as bad.

Methodically test from the solenoid, to the brushes, to the windings to pinpoint what part of the system is preventing starter operation. Replace components as needed.

Other Electrical Faults

Two other key components behind many electrical issues:

• Bad Regulator/Rectifier – This unit controls charging output to the battery. Failure can cause charging system issues or kill batteries. Test the regulator output and replace if voltages are out of spec per your manual.
• Faulty Stator – The stator generates electricity for the bike while running. Bad winding insulation and debris can short it out. Inspect stator windings for faults and replace the stator as necessary.

Monitor charging system voltage to catch regulator/rectifier issues before they take out your battery. Check stator windings during engine inspections to avoid being stranded on the trail.

Protecting Your CFMoto 500 Investment

Now that we’ve covered some of the most common CFMoto 500 problems and how to diagnose and fix them, let’s discuss some proactive maintenance tips to avoid issues in the first place:

• Follow the maintenance schedule – Your owner’s manual outlines specific service intervals for fluid changes, valve checks, belt replacement and more. Stay on top of maintenance to prevent accelerated wear.
• Inspect and replace wear parts – As components like brake pads, tires, filters and bearings wear, replace them to avoid more damage. Tackle issues early.
• Wash regularly – Mud, dirt and dust are an ATV’s worst enemy, causing accelerated wear and cooling issues. Hose off the chassis and check key areas.
• Use quality fluids – Don’t try to save a few bucks on cheap oils or coolant. Stick with manufacturer recommended fluids for performance and longevity.
• Learn proper riding skills – Don’t ride above your experience level. Attend a safety course and stay within reasonable speed limits to avoid accidents.
• Install protective mods – Hand guards, chassis skid plates, radiator guards and more protect from trail damage. Worth the investment!

Put in the time for proper maintenance and ride responsibly, and your CFMoto 500 will deliver years of reliable trail-conquering performance.

The Bottom Line

WhileChinese quads like the CFMoto 500 can present some reliability concerns, many issues can be avoided with diligent maintenance and protective mods. Fixing problems promptly also keeps small issues from becoming major.

Equipped with this detailed guide to common CFMoto 500 problems, you can now confidently diagnose and repair engine issues, transmission troubles, suspension woes and electrical gremlins. Here’s wishing you and your CFMoto many more trouble-free miles on the trails!

Let us know in the comments if you’ve experienced any other problems we should add. And please share if this guide helped you fix your ailing CFMoto 500 ATV!