Mine takes more than 3L from an oil change, I like mine to read on the half way mark on the stick. If you have put 3L in and ran it for a while and it don't show add some more until it does. Make sure your run it for a bit, then wait a bit to get the reading.
Current KTM 950 Adventure S 03
Old Suzuki TS50, Aprilia Chesterfield RS125 , Honda NC30, Cagiva Elefant 750