I've bought an older Major for single dosing, but are experiencing some peculiarities
-Narrow espresso range: Brew espresso at setting '4', +/- only 1mm of adjustment
-After taking off and replacing the upper burr carrier, the burrs will lightly touch at '4' but if tightened as far as it goes ('2.7') with the grinder off the burrs will afterwards only chirp at '3.7' (very close to the espresso setting)
-The grinder stops in 1s when switched off (my San Marco SM97 will run for 5 seconds before coming to a halt despites being much lower rpm)
-only about 1/8 of the espresso by volume is crema vs 1/3 for my sm97

The burrs have not been replaced but feel very sharp (almost same feel as my brand new SM97 burrs and much sharper than my K30 burrs which are still making great espresso). Tested with a marker, the alignment looks pretty good (here i've not tightened way down before running the grinder - perhaps I should)

The espresso looks decent in the bottomless portafilter, but it's not impressive in the cup. Compared to my SM97 there is more consistency and no unpleasant flavours, but generally much lower sweetness, and a muddied flavour with little clarity or aromatics.

Are these observations normal, or could there be an issue with the grinder?