13/11/2025
Did You Know This?
Read it and save it!⬇️⬇️⬇️⬇️
Why ATV or SSV is feeling sluggish or performance is not like promised?
And how to fix it?
Many times, there is big difference of two same model of unit.
At new completely stock units and especially when there are some modifications.
And usually when talking about bigger 1000 units the differences is bigger.
For example, let's take two exactly same GEN2 ZFORCE 950 SPORT
Both unit with same bigger tires and same clutch kit, but you can easily find that other is not performing the same?
The acceleration is slower on other one, and WOT RPMs (wide open throttle) is lower.
And it has belt slips and can even snap belts really easy.
Unit is completely new and doesn’t give any fault codes.
Why, it is like that???
Let's take another example, gen3 CFORCE 1000.
After 2000-3000km you’re lacking on speed and acceleration is slower that before.
Clutches are all good but somehow you are not still getting same speed and performance than when it was new?
Or two completely new Gen3 CFORCE 1000 units and other is clearly more responsive than other.
-First to check is valve clearance and then fuel pressure.
-After that if everything is good but you’re still wondering that what can cause the problem.
The most likely is that your O2 sensors are giving wrong information.
-Usually, these engines have given O2 fault at some point and that has goon away when just clearing the codes.
-Fault code clearing doesn't fix anything.
Its indicator that there is something wrong in the system.
-O2 sensors are little tricky many times.
In the ECU there is MIN and MAX value of O2 sensors reading (AFR) and many times there is miss reading in O2 sensors what is making engine fuel mixture too lean or too rich.
And most common is that its reading fuel mixture too lean and ECU self-adjusting makes correction and after that the fuel mixture is too rich.
-When Fuel mixture is too rich, it will kill engine torque and with CVT system what is based on torque sensing upshifting and downshifting, the results are reduced performance!
-At the same that too rich fuel mixture will usually burn your catalysator and that’s why just the new O2 sensors will not make any difference.
All this will eventually show as on poor performance and really hot exhaust headers. Header pipe can be red hot and you can feel your legs burning when driving...
This will eventually show as cracked header pipe.
Another symptom is when you get fuel in oil, extremely hot exhaust gasses, and again burn/melt catalysator in exhaust pipe.
And when catalysator elements have melted, it will block your exhaust flow and you see this first by poor engine power, bad throttle response and reduced top speed!
The basic is that if you have poor performance, there is always a reason for that!
Basic engines are always quite same when comparing those in engine dyno.
The real difference is cause of electronics, MAP sensors /O2 sensors / Fuel pump / Ignition coils or even your Battery!
If you have bad Battery and low voltage, the ECU go to safe mode and takes timing off from your engine to protect it!
If your WOT rpm is not the same than other same kind of units or you can feel that its lacking of power.
There is always reason for that!
Fault codes are excellent tool to find the problem but do not trust too much on just the codes.
O2 sensor can be bad and still not giving Fault code.
But luckily O2 sensors are cheap parts and easy to change.
First
-Check engine valve clearance.
-Then Fuel Pressure test
-Battery voltage
- Charging system
- Live data if possible!
And if all good, replace O2 sensors!
There is always reason if something is not working, we just have to find it and fix it.
-Ville from Vauhti Varikko-
Like, Share and remember to Follow for more information!
Vauhti Varikko
Iron Baltic ATV & UTV Accessories
Main Street Cycle
Jay Parts
