Music Hall mmf-7 spins faster


I have a Music Hall mmf-7 turntable (EAR 834P phono preamp) and it spins faster than normal. I bought a new motor and a new belt from Roy Hall, but it didn't change a thing. I borrowed my friends' motor (he has an mmf-7.1): no change... I even bought a Pro-Ject Speed Box (on Roy Hall's advice): it still spins faster. My cartridge is a Sumiko Blackbird. I really don't know what much else to do: any ideas? Did someone run into this problem?

I am desperate.
lrmellon
I like my MMF-7 -no problems whatsoever.

Lrmellon: Now you can swap all the parts from the new MMF-7.1 and see what happens.

I think the ".1" is a change to the tonearm.
The rest should be the same.

Good luck!
I am going to swap the motor, the belt, the sub-platter and the platter and see what happens.
I swapped the motor and, surprise, surprise: it is now much slower, almost not turning at all. I am going to change the platter and the sub-platter now.

Did I say weird?
Measure the diameter of the platter on both units. Try and find someone who has a set of calipers. They are used by machinsts to make precision measurments.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96509

I have a MMF-7 with the speedbox and am V happy with it, till I can get a VPI and then a Teres. ;)
I am currently away from home; I will resume all (measurements, swapping parts, etc.) upon my return next week. Thanks all.