Scoutmaster runs very slow

I have a Scoutmaster and the SDS. When I plug the Scoutmaster directly into the wall and measure speed with the KAB Speed Strobe 10 numbers drift by, moving right, in about 5 seconds. KAB states 10 numbers in one minute represents .3% accuraccy, so I'm really slow. Using the VPS, turned up to 66 frequency, 10 numbers drift by in around 15 seconds, better but still very slow. The voltage number reads 84. I would appreciate any suggestions
I read the last two posts. Two things:

1) Yes, you can dial the SDS up until you get to 33 1/3, but something is still wrong for the speed to be off by that much. I think it's worth getting to the bottom of. However, while you're debugging the problem, by all means ramp it up and get your records spinning!

2) If power delivery was the issue, I think your speed would be all over the map, rather than just slow. (Unless you live in a permanent "brown out" zone.)

Check the items mentioned in the previous posts, if platter, bearing, belts, etc. all check out fine then give VPI a call. They are very helpful.


I sent Mike at VPI an email. He said it sounded like a loose pulley and sure enough that was it. Speed is spot on now. Thanks for all your ideas.
I had a similar issue, but more like what Tom stated. My speed was all over the map and I figured it was a power delivery issue. I thought the motor was probably going bad. So I opened up the unit to find there was Hurst motor. Checked it out online. The motor I had was a 300 RPM 7.5 amp motor. They had the exact same motor and another one that was 9.5 amp and higher torque. Well, of course I had to go for the 9.5 amp version. What a difference. Speed is very stable now.