Piusi K33 Fuel Flow Meter - Calibration

Maaf numpang tanya saya punya flowmeter solar pak cuma setiap pengeluaran dalam 20ltr nya koq saya selalu rugi mohon bantuan nya tks

Hello!
They can demonstrate how to clean a K33 counter.
Very good contributions... Thank you

Reding 9 oil 10 ltr =1 ltr exra

Hello!
in 20 litres barrel says 21 litre in flow meter,
I tried to unscrew to - it rise to 21.6 litre or something in flow meter.
I changed directions back to + in maximum, it says 21 litre again and is tighten to + and again 21 litres. So in my calculation the flow meter says 4.75% more than is in real.
What is the accuracy in those k33?
The outside temperature was 24 to 25 degrees celcius.
Thanks!

Hello,
Help me
My calibration screw does not change the quantities neither + nor -
On what principle does it work?