It is indeed in the right groove, Eddaytona: the smaller one (and the larger one, as indicated, when I am using the Speed Box II).
Where is "as indicated" indicated?
The Speed Box appears to output 16 volts ac (VAC), while the MMF-7 appears to come with a 12 VAC wallwart power supply. I note that the ratio of 16 to 12 just happens to be approximately the same ratio as 45 rpm to 33.3 rpm. However the recommendation to use the larger pulley diameter with the Speed Box, for 33.3 rpm, would seem to make sense only if the motor speed were inversely proportional to supply voltage, which seems nonsensical. .
I don't know what kind of motor the MMF-7 has -- whether it is synchronous to the power line frequency, and what the sensitivity of its speed to line voltage is. But very conceivably it is different from the motors used in the Pro-Ject turntables for which the Speed Box is intended.
I would therefore do three things:
1)Try using the Speed Box while the belt is placed on the smaller rim of the pulley.
2)Try the 12 volt ac power supply from your friend's turntable.
3)Use a multimeter, set to measure ac volts, to measure the voltage provided by the power supply that came with your turntable, and compare it to what your friend's power supply puts out. Since you will probably have to disconnect the power supply from the motor to make that measurement, keep in mind that the voltage figures to be higher than it would be with the motor connected and running. Which is why I suggest comparing the readings of the two power supplies.
Re bearing oil, see page 14 of the manual for the 7.1, which I assume is similar to the 7 in that regard.
Regards,
-- Al