Troubleshooting the Top CFMoto Cforce 800 Problems

CFMoto Cforce 800 Problems

Have you recently purchased a CFMoto Cforce 800 all-terrain vehicle (ATV) and started experiencing some issues keeping it running properly? Don’t worry, you’re not alone. The Cforce 800 is a powerful sport utility quad with great towing capacity, but even quality machines like this can develop problems from time to time.

What are the most common CFMoto Cforce 800 problems owners run into, and how can you diagnose and fix them yourself? Fortunately, many Cforce 800 problems—like engine stalling, suspension noise, or overheating—can be resolved with some basic troubleshooting and maintenance at home. Read on as we walk through solutions for the most prevalent CFMoto Cforce 800 problems reported by owners.

Introduction to the CFMoto Cforce 800 ATV

Before we dive into troubleshooting common issues, let’s take a quick look at the Cforce 800 itself. This sporty ATV first launched in 2014 and is still part of CFMoto’s current lineup.

Some key features and specs of the CFMoto Cforce 800 include:

  • 793cc V-twin engine producing 61 horsepower
  • Continuously Variable Transmission (CVT)
  • On-Command 2WD and 4WD modes
  • Double A-arm independent front suspension
  • Swingarm rear suspension with preload adjustable shocks
  • Hydraulic disc brakes with dual-piston front calipers
  • Towing capacity of 1100 pounds

The Cforce 800 sits in the middle of CFMoto’s utility ATV range size-wise. It offers substantially more power than the smaller 400 and 500 models, but not quite as much brute strength as the largest 950cc variant.

The 800 is a good blend of sporty trail riding capabilities plus utility functions like hauling and towing. Its capable suspension soaks up bumps well, while the V-twin offers smooth power delivery even at high speeds or hauling heavy loads.

Common CFMoto Cforce 800 Problems

Even well-designed ATVs like the Cforce 800 can develop issues over time. Here are some of the most common problems reported by Cforce 800 owners:

1. Hard Starting or Not Starting at All

Difficulty starting is one of the most frequent complaints with the Cforce 800. There are a few key things that could cause starting troubles:

  • Battery: A weak or dead battery prevents sufficient power from getting to the starter. Check the battery voltage and connections. Clean any corrosion on the terminals and charge or replace the battery if needed.
  • Spark Plugs: Fouled, worn or faulty spark plugs can prevent starting. Check the plugs and replace if they are fouled, damaged or have over 100 hours of use. Verify the gap is set correctly.
  • Fuel: Starting issues are often fuel-related. Make sure there is fresh 87+ octane gas in the tank. The fuel should be drained and replaced if it’s over a month old. Inspect the fuel filter and replace it if clogged.
  • Fuel Pump/Injectors: Weak fuel pump output can make starting difficult. Listen for the pump’s hum when turning the key. If the pump is noisy or whining, it could be failing. The injectors may also not be spraying properly if clogged with deposits.

2. Engine Stalling or Running Rough

Another common problem is the Cforce 800 engine stalling or running erratically, especially at idle. Here are some potential causes and fixes:

  • Air Filter: A clogged air filter restricts airflow to the carburetor or fuel injection system, which can cause poor performance. Replace the filter immediately if it is overly dirty.
  • Spark Plug: In addition to hard starting, a fouled or failing spark plug can make the engine run rough or stall out during riding. Re-gap or replace the plug.
  • Fuel Issues: As discussed above, contaminated or low fuel, filter blockage or pump/injector faults can impact performance and idle.
  • Idle Speed: If the idle rpm is set too low, that can also cause stalling. Adjust the idle speed screw to around 1500 rpm.
  • Vacuum Leak: Any air intake components that have come loose or cracked can create a vacuum leak that disturbs air/fuel ratios and makes the motor run poorly. Check all hoses, seals and connections for leaks. Replace damaged parts.

3. Loss of Power

Over time, Cforce 800 owners may feel the ATV losing power during acceleration, hill climbing or while towing. Here are some likely culprits:

  • Air Filter: Just like with stalling issues, a severely clogged air filter robs the engine of airflow and power. Replace immediately.
  • Spark Plugs: Bad plugs misfire, resulting in power loss. Inspect and replace worn electrodes.
  • Fuel System: Contaminated old gas, filter clogs or failing injectors/fuel pump will lead to power loss.
  • Exhaust Blockage: Carbon buildup or other restrictions in the exhaust like a crushed pipe reduce performance. Check system.

4. Overheating Issues

It’s essential to keep these high-performance ATVs running cool. Overheating problems usually stem from:

  • Low Coolant: Periodically check the coolant level. Top off if low and bleed air from the system. Make sure the radiator cap forms a tight seal.
  • Cooling System Leaks: Watch for leaks from hoses, radiator or water pump. Fix any cracks or loose connections. Pressure test system if necessary.
  • Dirty Radiator: Clean off mud or debris from the radiator fins and intake screens. Flush system if coolant is contaminated.
  • Water Pump/Thermostat: Faulty water pump impeller or a stuck thermostat prevents circulation. Test both and replace if not operating properly.
  • Cooling Fan: If the fan motor fails or spins slowly, that allows overheating. Test fan speed and replace fan if required.

5. Suspension Problems

The Cforce 800 uses quality KYB shocks, but the suspension can still develop issues like:

  • Leakage/Blown Shocks: Oil leakage or totally blown shocks lead to a soft, bouncy ride. Visually inspect shocks and replace any that are leaking fluid.
  • Sagging Springs: Over time, the suspension springs may sag. This allows excessive leaning during cornering. Check ride height and if uneven, replace sagging springs.
  • Unbalanced Tires: Improper tire pressure in just one tire upsets the balance of the suspension. Always inflate tires to the recommended PSI.

6. Braking Issues

Strong braking performance is obviously crucial for controlling these quick ATVs. Some potential braking problems include:

  • Worn Pads: The brake pads take the brunt of wear. If excessively thin, they lose stopping power. Check thickness and change pads under 2 mm.
  • Sticking Caliper: The caliper piston can seize up over time, causing uneven pad wear and stopping distances. Lubricate caliper slider pins.
  • Air in Lines: If air gets into the hydraulic lines, the brake lever and pedal will feel spongy. Bleed the system to remove air bubbles.
  • Low Fluid: Keep the master cylinder reservoir topped off with DOT4 brake fluid. Low fluid allows air in the lines.

Step-by-Step Diagnosis and Repair of Common CFMoto Cforce 800 Problems

Now let’s move on to actually diagnosing and fixing the most prevalent issues with the CFMoto Cforce 800 using a step-by-step approach.

Hard Starting Troubleshooting

Difficulty getting your Cforce 800 to start is frustrating and takes the fun out of riding. Work through these key troubleshooting steps:

Step 1: Confirm the engine stop switch is in the “run” position.

Step 2: Check the battery voltage with a multimeter. It should be 12.8+ volts when fully charged. If low, charge the battery or replace it if it no longer holds a full charge.

Step 3: Examine the spark plugs. Look for a wet, black or fouled insulator tip which indicates bad plugs. Check the gap too—ideal is 0.8-0.9mm. Replace plugs every 100 hours of use.

Step 4: Remove, inspect and replace the air filter if dirt is visible. Clogged filters make starting difficult.

Step 5: Drain old gas and refill with fresh 87+ octane if the fuel is over a month old. Old gas causes hard starting.

Step 6: Remove and check the fuel filter inside the gas tank. Replace if it looks dirty. Debris in the filter prevents sufficient fuel flow.

Step 7: Spray carb or throttle body cleaner onto the throttle plate and bore. This removes gum, oil and carbon buildup that affects starting.

Following that process should resolve most starting problems. If it still won’t start, further testing of the fuel pump, injectors and sensors may be required at a CFMoto dealer.

Fixing Engine Stalling and Running Rough

When your Cforce 800 stalls out on the trail or won’t idle smoothly, it’s time for diagnostics:

Step 1: Inspect the spark plugs again as fouled or worn plugs can cause stalling. Replace if needed.

Step 2: Confirm the idle speed is around 1500 rpm. Adjust the throttle stop screw if too low. Low idle rpm leads to stalling.

Step 3: Remove and check the air filter. Tap it to remove dirt or just replace it if excessively dirty. Restricted airflow causes poor engine performance.

Step 4: Check for debris built up in the fuel injectors. Use fuel injector cleaner kit to remove gum and varnish.

Step 5: Ensure the fuel tank vent line is clear so pressure doesn’t build up in the tank and fuel flow is disrupted.

Step 6: Spray carb or throttle body cleaner on the bore and throttle plate following the steps above. This cleans out oil deposits.

Step 7: Inspect all rubber intake components for cracking or loosening which indicates a vacuum leak. Tighten all clamps and replace damaged parts.

These basic engine and fuel system checks should locate the cause of rough running or stalling problems. Schedule dealer service if the issue persists.

No Power Acceleration Troubleshooting

Gradual power loss is common as engines wear or dirt builds up in intake and exhaust components. Follow this process to restore lost pep:

Step 1: Examine the air filter again. Even a partially clogged filter will reduce power substantially. Replace it.

Step 2: Remove and inspect the spark plugs for excessive wear or fouling. Replace worn plugs.

Step 3: Check the fuel filter inside the gas tank. A restricted filter reduces fuel flow. Replace if dirty.

Step 4: Add fuel injector cleaner to a full tank of fresh gas to remove injector clogs. Run engine to circulate cleaner.

Step 5: Check exhaust pipe and muffler for dents or damage causing blockages. Repair or replace damaged sections.

Step 6: Use an exhaust port cleaning tool to clear away carbon buildup inside the port. Carbon restricts exhaust flow.

Step 7: Consider replacing the fuel pump if it sounds strained or whiny indicating reduced pump pressure.

If you still notice power loss after this process, compression and leakage testing may be needed to check the piston rings, valves and cylinder head gasket.

Overheating Issues Diagnosis

An overheating CFMoto Cforce 800 can leave you stranded on the trail. Follow this structured troubleshooting approach:

Step 1: Check coolant level in the overflow tank. Refill if low and bleed the system to remove any trapped air bubbles.

Step 2: Examine the radiator cap seal for cracks or damage. Replace cap if gasket is hard, misshapen or leaking. The cap must maintain system pressure.

Step 3: Flush contaminated old coolant and refill with a 50/50 mix of coolant and distilled water. Old coolant loses effectiveness.

Step 4: Pressure test the cooling system to check for leaks. Inspect hoses, radiator, water pump seals and gaskets. Repair any identified leaks.

Step 5: Remove debris blocking air flow through the radiator like mud or grass. Use compressed air to blow out dirt between cooling fins.

Step 6: Test the water pump impeller shaft for tightness. If it spins loosely the impeller needs replacement.

Step 7: Check the cooling fan spins freely and kicks on when hot. If not, test fan motor and thermostatic switch.

Sticking to this process will catch most overheating issues before they strand you on the trail. Schedule repair shop service if problems persist.

Suspension Noise and Handling Diagnosis

Harsh suspension impacts and uneven handling can make riding uncomfortable. Here are tips for smoothing out the ride:

Step 1: Clean dust seals and check all shocks for leaking oil. Replace any shocks showing visible fluid leakage.

Step 2: Confirm rear spring sag is even on both sides when unloaded. Uneven sag indicates one spring needs replacement.

Step 3: Bounce each corner aggressively checking for uneven rebound. If one corner is slower, the shock needs rebuilding or replacement.

Step 4: Ensure tires are inflated equally on each side to recommended PSI for proper balance and stability. Uneven pressures lead to handling issues.

Step 5: Torque all front suspension pivots and steering stem bolts to spec to eliminate clicking noises during bumps.

Step 6: Lubricate rear swingarm, suspension and steering stem bushings if squeaking. Use rubber lubricant, not WD-40 which attracts dirt.

Following this structured process simplifies diagnosing suspension and handling problems. Contact a dealer for major rebuild or replacement needs.

Brake Issues Troubleshooting

Braking problems can make the Cforce 800 dangerous to operate. Follow these logical steps for diagnosis:

Step 1: Check thickness of brake pads. Replace if worn under 2 mm thick to restore stopping power.

Step 2: Inspect brake rotors for excessive wear, scoring or warping. Resurface or replace rotors if badly damaged.

Step 3: Lubricate caliper slider pins so the caliper moves freely. Seized calipers cause uneven pad wear.

Step 4: Check brake fluid reservoir level and refill with DOT4 fluid if needed. Low fluid allows air into brake lines.

Step 5: Bleed brakes if pedal or lever feels spongy. Air trapped in lines causes spongy feel.

Step 6: Flush and replace brake fluid if over 2 years old. Old fluid boils at lower temperatures and causes soft brakes.

Methodically following these brake troubleshooting steps will ensure safe, consistent braking performance on your CFMoto ATV.


While the CFMoto Cforce 800 is well engineered for durability, common issues can still pop up like hard starting, lack of power, overheating or suspension problems. The good news is that you can troubleshoot many Cforce 800 problems yourself using a systematic approach. This saves time and dealer diagnostic fees.

Regularly replacing wear parts like spark plugs, air filters and brake pads goes a long way towards avoiding issues in the first place. But following the structured troubleshooting processes outlined above will get your ATV running smoothly again while building your confidence as a do-it-yourself mechanic!

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