VPI motor - upgrade to 300 rpm?


I hsve a HW-19 mk 4 plus or something, with the Black knight platter and inverted bearing, along with the SDS, The SAMA is the Hurst 600 rpm. This has run, now, for five years. Recently I have had problems with pitch variation, not easy to locate. The problems have been somewhat solved by glueing the pulley to the shaft and by oiling the motor, helping a lot, but perhaps not fully. Should I order a 300 rpm motor and new pulley? Advice is appreaciated, especially, experiences going from the 600 to the 300 rpm motor.
Ag insider logo xs@2xo_holter
Yes, true, the newer SAMA from what I can see as well, is basically empty. Nothing inside, but a Foam Sheet isolating-seperating the bottom of Motor Case from the Run Capacitor.

But, the 600rpm Motor is not inheritly bad as far as speed stability goes, and if working properly, is not prone to the large degree of speed variation that you are appearing to notice.

So, with that said, yes, the Motor could be at fault, and I imagine if it is doable, one could then possibly opt for either the 300rpm Motor, or otherwise, a new 600rpm Motor should do the trick.

It will be VPI that may have to answer your questions, if the 300rpm Motor will be a simple swap, or will one have to modify the SAMA Case in order for it to fit? We can assume that a different Pulley would indeed be needed. The question is, does VPI have the correct Pulley that will work with a SAMA. Meaning, will it be long enough to protrude far enough, and up through your Plinth to reach alignment with Platter? That is an unknown to me?

Having to glue the pulley, I then assume you once had either slippage, or wobbling of the Pulley, to require gluing it to the Shaft?

I think we can all agree, that the Base on which your Table, and SAMA rest upon should not be an influence of the Motor's speed stability, that this would be caused by something else? But what?

The only other influence that I can think of, in regards to speed fluctuation, would be the VPI SDS at fault? One would have to test the SDS to find if any fluctuations in voltage and/or line frequency are taking place?
Mark
If you have an SDS then there is one other thing I can highly recommend that you try. Get rid of that vibration prone VPI rubber belt and find some silk thread. Tie a basic knot in the ends and use that instead. You will definitely have to adjust the speed to compensate for the thread's smaller diameter sitting down in the pully groove. You will also definitely need to give the platter a push-start by hand.

The PRAT will increase dramatically, with more detain and better space and air. Not a small improvement and easily one of the best things I did for my VPI.

Thanks! I think PRAT is what I am looking for, and want to try the silk thread variant. What kind of basic knot do you use?
The question remains, what is the best motor, is there a sonic profit with 300 rpm? Since no-one here has answered, I have mailed VPI about this.
Here's a thread discussion thread (sorry, I couldn't resist) but there are others and some that have on-line sources quoted.

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1264987921&openfrom&1&4#1