6 Most Common CFMOTO CFORCE 400 Problems and Effective Fixes

The CFMOTO CFORCE 400 is an entry-level ATV for off-road enthusiasts. It features a powerful engine, a reliable suspension system, and a state-of-the-art design.

And with all its impressive modern features, this ATV is one of CFMOTO’s budget-friendly options. However, the CFORCE 400 is not immune to problems. The most reported CFMOTO CFORCE 400 problems are overheating, starting issues, poor throttle response, vapor lock problems, excessive heat from the exhaust, and brake issues.

So, what should you do if your CFORCE 400 has an issue? Herein is a detailed CFMOTO 400 troubleshooting guide.

Starting Issues

Starting problems are common in your CFORCE 400 after using it for an extended period. The ATV tackles challenging terrains, making its part more prone to failure. If your ATV’s engine doesn’t start, it might have the following issues:

  • Dead battery
  • Corroded battery terminals
  • Loose connections
  • Clogged carburetor
  • Defective spark plugs

How to fix:

The battery should be the first component to check if your ATV has starting problems. A multimeter should help you check for low voltage. Charge the battery overnight to see if low voltage is the cause.

If the battery won’t charge, inspect the terminals for clogs. Use baking soda or a terminal cleaner to remove the clogs.

Next, inspect the grounding wire on the battery to see if it’s loose or defective. Tighten if loose or replace it if faulty. If the battery doesn’t charge after these fixes, it might be bad and requires replacement.

Another component to check is the carburetor. A clogged carburetor prevents fuel from reaching the engine, causing starting problems in your CFORCE 400 ATV. Clean the carb with water and a microfiber towel if it appears dirty or clogged.

If the starting issue persists, check for defective spark plugs. If they appear burnt, replace them with iridium spark plugs.

Vapor Lock Problems

Vapor lock issues occur when hot fuel in the ATV’s fuel line turns into vapor, causing the engine to stall. In most cases, the fuel gets too hot due to an overheated engine or when riding in hot weather.

The primary causes of vapor lock problems include the following:

  • Clogged fuel filter
  • Malfunctioning fuel pump
  • Improper positioning of fuel line

How to fix:

To fix vapor lock issues in your CFORCE 400, inspect the fuel filter and the entire fuel lines for clogs. Clean the fuel line and replace a clogged fuel filter. 

If you have a malfunctioned fuel pump, replace it with an electric pump.

Next, wrap the fuel line with a heat shield to prevent high temperatures from heating the fuel. Alternatively, you can direct the fuel line away from the engine compartment.

Also, add an effective fuel stabilizer into the tank to make the fuel less volatile. If possible, use a higher octane fuel to minimize the chances of fuel lock issues.

Poor Throttle Response

Poor throttle response is among the most common CFMOTO CFORCE 400 problems. It’s also a common issue with other CFORCE models like the 500 ATV.

When this problem occurs, the engine fails to respond quickly at full throttle. This problem renders the high gear useless, forcing riders to rely on low gear. Poor throttle response results from clogged fuel injectors, a dirty air filter, or a defective throttle position sensor.

How to fix:

A dirty air filter restricts airflow resulting in a sluggish response. Check if the filter is dirty and clean it.

If your ATV has clogged fuel injectors, clean them to remove any deposits. You’ll also need to clean the fuel system to remove dirt and debris.

If the throttle issue persists, your ATV might have a malfunctioning throttle position sensor. Test it with your multimeter to see if it’s defective, and replace it if necessary.


The CFORCE 400 might overheat with time, especially when owners neglect maintenance. Overheating can occur after overworking the ATV or riding it in hot weather.

Your ATV might overheat due to the following reasons:

  • Low coolant level
  • Dirty radiator
  • Air in the coolant system
  • Blown head gasket

How to fix:

Start by checking the coolant level to see if it’s low. Add coolant to the reservoir if necessary. Then, inspect the reservoir for signs of leaks and repair the leaking areas. You can also check for a blown head gasket that might cause the coolant to leak. If you have a blown head gasket, replace it.  

The other component to inspect is the radiator. A clogged radiator blocks airflow, making the coolant ineffective. If you have a clogged radiator, clean it with a hose and remove any gunk with a cleaning solution. Then, replace the radiator fins if they appear damaged.

If the overheating issue persists, the coolant system might have an air pocket blocking the coolant flow. You can fix this by bleeding this air out of the system.

Brakes Issues

The CFORCE 400 can develop brake issues with time after tackling challenging terrains. The most common brake problems with this ATV include the following:

  • Worn brake pads
  • Brake fluid leaks
  • Brake calipers sticking

Like most CFMOTO CFORCE 400 problems, you can prevent brake issues with regular inspections and maintenance.

How to fix:

If you notice your ATV has brake issues, check for worn brake pads and replace them if necessary. Brake pads will quickly wear if you overuse your ATV on rugged terrains. So, if it’s long since you replaced them, they might be worn.

Low brake fluid levels can also cause issues with the brake system. Inspect the brake line and calipers to see if there are leaks. Repair or replace any leaking part to make the brakes effective.

If the brake issue persists, check for a stuck brake caliper. Sticking brake calipers can damage the brake rotor and cause uneven wear of the brake pads. If the calipers have dirt or debris, clean them. You can also replace them if they appear damaged.

Excessive Heat From the Exhaust

The exhaust pipe of the CFORCE 400 gets excessively hot during long rides, causing riders discomfort. The heat warms up the fuel tank and the outer plastic shell. As a result, riders cannot keep their right leg in place without getting burned.

How to fix:

Cover the exhaust pipe with a heat shield if riding becomes uncomfortable due to the excessive heat. The heat shield will reduce heat burning the plastic shell and fuel tank.

You can also take your ATV to a dealer or mechanic to replace the exhaust pipe. Look for an aftermarket option that directs heat away from your leg. Alternatively, buy heat-resistant riding pants that protect your legs from excessive heat.

Final Thoughts

While the CFORCE 400 is a reliable ATV, it’s prone to various issues affecting its performance. Luckily, most CFMOTO CFORCE 400 problems are easy to diagnose and fix. Follow the above fixes to resolve these problems, or contact your local mechanic for help. You must also maintain your ATV regularly to enjoy trouble-free riding experiences.