The bearing and well are key to keeping the unit from running slow. The michell gyro inverted bearing has a pumping system that moves oil up tothe bearing. low oil or dirty oil can cause issues The other possibility is the bearing is bad. It is unlikely, but I have seen that once on my michell.
Michell Gyro Se running a little slow
I have noticed that some songs sound slower off my table than they should. This is most evident on Led Zeppelin's Whole Lotta Love, Simon & Garfunkel's Cecelia and The Smiths' Frankly, Mr Shankly. Most of the time, the difference is not noticeable, but on some songs I can pick it up. I'm not sure what the problem is. I have the external power supply but am not sure if that is the issue.