The result of last successful tune is:
Last CPU clock is: 6100 MHz
Last HT Link ref. clock is: 200 MHz
Last CPU multiplier is: 30.5 X
I did not boost it. Cooler fan is not enough for this action i think.
No it is not normal for your processor to run at 1400 MHz unless it or the VRM circuit is overheating. The AMD boxed fan can cool whatever CPU it is shipped with if properly installed and you have sufficient airflow thru your PC case to remove the hot air from the CPU and GPU coolers. Make sure that your fan settings are at Maximum or 100% in the BIOS or Win10 so the fans can run at full speed when necessary.
Did you confirm that your mobo BIOS supports the FX-8300 model CPU? If not then you need to update the BIOS to a proper version so that it can identify the CPU and properly set the vcore and frequency on boot. You will want to clear CMOS if you had a different CPU installed on this mobo previously.
You can use the applet OCCT to record the processor vcore voltage, frequency internal core temp and other criteria to see exactly what is happening with you CPU. If the VRM circuit is overheating adding a small fan blowing on the VRM components may fix the problem, if the VRM overheating is the source of the problem.
The numerous FX-8000 series CPU overheating threads here cover all of the typical heating issues with FX 8-core CPUs. The basic parameters and diagnostic procedures are the same for all FX-8000 models.
The CPU can and will change frequency based on load and temp. It is possible for the CPU to run at 1400 MHz if it is at idle but it should not run at 1400 MHz when under load.