12 Most Common CFMOTO ZFORCE 800 Problems


Made by KTM’s production partner, CF Moto, the CFMOTO ZFORCE 800 is more than your average Chinese four-wheeler. It is an excellent utility vehicle that can compete with big names in the ATV industry. But being a new player means that it has not yet perfected its vehicle structure and design, which established name brands are closer to accomplishing.

Problems usually come from vehicle abuse, riding style, or lack of maintenance. They include engine noises, parts failure, and general wear and tear. If you are buying a used ZFORCE 800, check the rear lower A-arms and engine brakes. Make sure to inspect the CVT belt as well if it needs replacing.

Here is a list of the most common CFMOTO ZFORCE 800 problems that you should be aware of:

  1. Unstable idle speed
  2. Abnormal acceleration
  3. Poor brake performance
  4. Engine does not start
  5. Bad engine noise
  6. Difficulty in starting the engine
  7. Insufficient power
  8. CVT noise
  9. Severe front/rear-wheel runout
  10. Front/rear suspension too soft/hard
  11. Loss of power steering
  12. Engine overheating

While this article focuses on the problems, half (if not most) do not seem to occur for more experienced, seasoned riders. So, in a way, preventing these issues and bringing the most out of the quad’s reliability entails a certain level of mechanical intellect and skill. Read on to know more about the CFMOTO ZFORCE 800.

CFMOTO ZFORCE 800 Problems


1. Unstable Idle Speed

A lot of CFMOTO owners find the vehicle’s idle speed unstable during or after the warm-up period or at any time. At times, idle speed issues occur erratically whenever electric components are switched on or are too high. Unfortunately, there is no means to adjust engine idle speed due to the vehicle’s fuel injection system, requiring adjustments to be set at the factory. Contact your dealer for service immediately if you observe abnormal idle speed settings, as this may result in poor engine performance and damage. Take note that your ZFORCE engine idle speed should be 1300 RPM ± 100 RPM (at operating temperature).

2. Abnormal Acceleration

While ATV/UTV magazine tests have mostly positive feedback for the vehicle in terms of acceleration, the reverse is true for riders who have ridden the 4×4. There are instances when acceleration feels restrained and underpowered, even for brand-new vehicles. The CFMOTO ZFORCE engine is consistently stellar at low speeds, which is a shame. Experienced owners point newbies toward checking if their ZFORCE has bad gas or a bad throttle position sensor, or if they ride in very dusty areas. Checking on the valve, fuel lines, stock air filter, or fuel filter would be about the extent of the first-line inspection. If there are no issues found, go to your nearest dealer for assistance.

3. Poor Brake Performance

Weak brakes are among the CFMOTO ZFORCE’s glaring problems. While we can expect brakes to not perform as exquisitely within break-in, the same should not be true after the said period. Riders would almost immediately replace the brake pads to rectify the problem. But the correct fix is to bleed the brakes (to get rid of all the air inside) and change the brake fluid. Doing these two simple steps will improve your quad’s stopping power significantly. Not to mention that these are easy and economical fixes.

4. Engine Does Not Start

With this issue, the engine either cannot rotate or rotates but cannot start the engine. And in rare cases, the problem is accompanied by error codes P0122 and P0351-P0352. Usually, a low ignition circuit or ECM voltage, weak battery, or not enough voltage getting to the coils cause a no-start issue. It could also stem from oil in the engine (say, after you tear the air filter box to be able to add a snorkel on your quad). Check the cable connections and the main fuse, then test before and after the fuse while cranking to see if the voltage is lower than 12V. If it is, then that would explain why the engine will not start. Otherwise, you may need to troubleshoot specific to the error codes given off by the ECM.


5. Bad Engine Noise

Loud knocking or rattling sounds could indicate valve train, connecting rod/bearing, pressure sensor, or oil filter issues. It would be best for you not to attempt restarting the machine if your engine noise sounds severe. Investigate what is causing the engine noise, and prepare to pull down your quad in the process. Check that the oil filter does not contain any metal flakes or other kinds of obstruction. Inspect the clutch plate if loose as it can sometimes cause this problem. If your four-wheeler recently underwent a rebuild, then chances are the rattling sound results from substandard or incorrect parts, fasteners improperly torqued, EFI box incorrectly tuned (or running lean), or the previous builder messing something up during the last rebuild.

6. Difficulty in Starting the Engine

Tell-tale signs include your machine not turning over, difficulty starting when the temperature is either too warm or cold or an inaudible fuel pump. You may also feel that the rev limiter is always on or may notice patterns when it occurs (for instance, in forward or reverse). You can narrow down the cause of the problem by ensuring that your RPM is okay and that fuses, battery, sparks, and cable connections all check out. Most of all, make sure that your kill switch is not acting up, as it is usually the culprit. Not thoroughly cleaning your wheeler after mudding can cause starting problems too.

7. Insufficient Power

This is one of the trickier CFMOTO ZFORCE 800 problems and entails a lot of procedures to fix. Given the vehicle’s setup, symptoms may overlap with that of a no-start issue, and it takes a trained, discerning eye to know the difference. Based on most riders’ experience, fuel starvation is the trigger, but this may not always be the case. To find the root cause, do the following steps:

  • Crank the engine with the air cleaner off and spray carb cleaner (or its equivalent) in the throttle body – to isolate the fuel problem and determine if you are getting a lean/rich mixture.
  • Following the above step should make the engine start. If it does not, but you are getting spark, pull the plugs, and do a compression test. You will need a deep sparkplug socket (at least 5/8) to remove the rear plugs.
  • Pull the cap off the tank and turn the key on (the fuel pump should run a bit then shut off). If it starts, look to the vent and check that the tank’s valve is not stuck shut.
  • Follow troubleshooting steps for a no-start issue to rule out which route you do not need to progress into further. Ensure the battery is fully charged (a battery tender is very handy in these situations).

Owners who are more than an hour’s drive away from the nearest dealer or local mechanic normally do the poor man’s compression test (putting their finger over the plug holes while cranking the engine to feel for pressure) to determine which of the plugs need more work. Use a real gauge instead, as it makes things a tad easier and compression test readings more accurate.

8. CVT Noise

This is not automatically an issue, as the CFMOTO ZFORCE may have a standard whining clutch, typically at idle speed or during transmission. But if you feel your machine sounds like a wood planer, then something may be wrong with your rear axles. To determine if there is an actual problem, check gearcase and differential oils (best to change them to a synthetic 80/90 or 75/90), play or movement in bearings and CV joints, and end play or side play movement in the pinions. Your rear differential could also be too tight and may need to loosen up, and the shims need to replace. Loosening the adjuster on the differential casing also has the same effect – one of these steps should minimize noise drastically.

If, by any chance that the gearing noise is unpredictable, then you may need to inspect other parts. Among these are motor mount bolts, gear shifter linkage (for proper alignment), rubber parts of the engine mounts, cover bearing, and engine brake (to check if this is the source of the noise). Many ZFORCE 800 owners, together with their dealers, conclude that the H gearbox is either worn out or does not engage correctly. The worst-case scenario is an alignment problem or a bent fork in the transmission. Adjustments cannot correct this and will require replacement parts.

9. Severe Front/Rear-Wheel Runout

Bouncing or shaking at speeds above 20 mph is a sure indicator or a wheel runout. Several factors can cause excessive wheel runout – these include the rim, wheel/tire mounting, and improper seating (sitting in your garage too long included). Severe use, such as prolonged heavy load operation and commercial functions, also add to this problem. A standard fix for this is to rotate the wheel and tire assembly a certain number of stud positions on the hub or to rotate the tires 180 degrees on the wheel. Spraying some silicone spray in gaps between the tire bead and the wheel bead edge (and airing up the tires to 30 lbs) helps too. Just do not forget to put the tires back to their recommended psi.

10. Front/Rear Suspension Too Soft/Hard

A flaw in the lower rear A-arms best explains the occurrence of this issue. According to CFMOTO dealers, a hole in the lower rear A-arms bushing tube allows grease to travel away from the (inside) bushing into the A-arm frame for all 800-class CFMOTO models. Although this is an acknowledged issue, all A-arms are constructed the same way, leaving dealerships with no replacement or fix for the problem reported by unit owners. The superficial fix is to grease these parts before every ride. CFMOTO eventually released a bulletin stating it would cover repairs to the faulty lower A-arms.

Ensure any brand-new CFMOTO ZFORCE purchases to make sure the lower A-arm issue has been corrected. If you happen to own a secondhand unit, it will be in your best interests to know how to deal with this problem. Real Talk Powersports shares tips on suspension setup adjustment for a CFMOTO ZFORCE 800 in this video:

11. Loss of Power Steering

Several riders have encountered EPS issues with barely 200 miles on their four-wheelers. The vehicle steers weird when the EPS quits or stops working when making right turns. Dealerships told them that it was partly due to a design flaw. An EPS sensor shuts down when the tire hits something hard, causing the EPS to not function. This issue, however, can easily be corrected with an ECM replacement. 

Additionally, others look at the shifter linkage. Replacing the ECM resolves the problem but so does changing the way you operate the controls. When shifting to low, keep light pressure on the shifter while getting on and off the throttle. This way, the shifter snicks into gear, never pops back out, and produces unpleasant grinding noises. Recognizing the feel when the shifter nicks into low also help.

12. Engine Overheating

This is an issue common to almost all 4×4, especially purpose-built ATVs and UTVs. The more tasks a quad can do, the easier it is to overwork and neglect the engine’s upkeep, which can cause it to overheat. Generally, a cooling system leak, soiled radiator fan, broken water pump, or clogged coolant hose can cause heat not to escape the CFMOTO ZFORCE 800 engine compartment. Using high gear for continuous slow speed travel or towing can also lead to excessive heating of the clutch system or damage engine components.

Here are some tips to keep your ZFORCE 800 engine from overheating unnecessarily:

  • Your radiator should have enough coolant and be regularly inspected for damage.
  • Install a high-pressure radiator cap or a digital radiator fan.
  • Have a recovery tank to serve as an excess coolant reservoir.
  • Go for a durable aftermarket water pump and impeller, or make sure that the stock water pump spins freely.
  • At any point that you experience an unusual loss of power or ticking noises while driving, turn your engine off. This will prevent engine lubrication from completely drying and pistons from seizing.
  •  Be mindful of ambient temperature when riding.

Other CFMOTO ZFORCE 800 problems include loud noise from the exhaust system or shock absorbers, oil consumption is too high, or pressure is too low, engine oil whitening, CVT belt wear, and other EFI issues. Others are either self-inflicted or due to wear and tear. For instance, the radiator fan not turning on may be due to dirt, obstructions, or bent vents. Likewise, headlights not turning on may be due to insufficient voltage to the headlights or burnt lighting. For CVT belt issues, here is a helpful video by Husqvarna motorcycle shop:

2018 CFMOTO ROV Recall

On October 31, 2018, 1,800 units of recreational off-road vehicles or ROVs, including ZFORCE 500 Trail, 2018 ZFORCE 800 Trail, and 2018 ZFORCE 1000 SSV, were recalled due to a probable crash hazard. The throttle pedal shoves past the throttle stop for these vehicles and does not return to the idle position, making for continued acceleration.

Conclusion – CFMOTO ZFORCE 800 Problems

In summary, here are the most common CFMOTO ZFORCE 800 problems:

  1. Unstable idle speed
  2. Abnormal acceleration
  3. Poor brake performance
  4. Engine does not start
  5. Bad engine noise
  6. Difficulty in starting the engine
  7. Insufficient power
  8. CVT noise
  9. Severe front/rear-wheel runout
  10. Front/rear suspension too soft/hard
  11. Loss of power steering
  12. Engine overheating

Luckily for new owners, there are tons of online tutorials, forums, and support from the riding community that provide a wealth of support. However, it would be an added help if CFMOTO provides thorough troubleshooting information in service manuals for all their vehicle models. For instance, I have noticed that the CFMOTO Terralander 800 offers detailed steps on addressing common issues, while the owner’s manual for the CFMOTO ZFORCE 800 falls short on this aspect.

The CFMOTO ZFORCE 800s receive a lot of love and hate from consumers, and none is to blame. All these positive and negative feedback are predominantly from personal experiences and are solid bases for drawing one’s conclusions about the 4×4. In general, the CFMOTO ZFORCE is a reliable quad. Given proper care and maintenance, it will faithfully serve any rider many years on the trails. These wheelers have a quality, functional design that makes them perfect workhorses and weekend rides.

Kris Peter

Adventure seeker and off-road enthusiast. I love the thrill of going off-road and taking on the elements.

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