I'm very happy for you! I've had mine since '77, they need some sewing machine oil every few years. I highly recommend you not use it till you get some oil in that motor. Do a search on putting oil in the motor in the 125 MKII. It's pretty easy, lock the arm, flip the TT over, heavy bitch ain't it?
Remove the ... particle board base.
There is a tiny hole to put a few drops of oil in there, that should help your slow start issue...are you sure the belt is the right one?
It should last you till you get called home many years from now, you will not find anything better unless you want to spend $10,000+, enjoy!!
Yes, it is one heavy table for what it looks like.
The bottom cover, this needs to go. One improvement on the TD-160 Super over the TD-160 was replacement of the hardboard bottom with a chunk of thicker MDF. I believe the same can help the 125. I use mine without a bottom cover right now.
This speed adjustable Thorens is one of the few Thorens tables that can compensate the speed when using a non-Thorens belt. All non-Thorens belts I have tried on my TD-160 Super provided inaccurate speed. There will be different start characteristics with a non-Thorens belt that would effect the 125, though.
Recapping these today is something that makes the electronics respond better. The speed can be set to center the speed adjustment wheel, the neon lamp comes on immediately, the table starts right up and well it is just better, like it is supposed to be. On Mike's table, I upgraded the older board (still a Mk II version) to the one with fewer parts. This is a job described on AK at
http://www.audiokarma.org/forums/index.php?threads/td125-motor-stopping.348375/ Speed improvements included less clutch chatter if any, quick to speed and accurate speed from the start. All around just better.
As for the $10K spendable to replace the td with anything better. I know a Thorens guy who bought a Clear Audio (used, many upgrades got a deal) that had a combined retail of about 6k, I'll say it again, he got a deal. He says it is a 40% improvement in sound quality from his records. This was enough for him to swap the starter Graham Slee arm with a new arm. This teaches me that the 125/SME is a grand old table that can be beat without too much trouble but it will cost at least a few grand. And these 125s have new thrust plates, polished spindles, new oil for the motor and the spindle, one with a nice new thicker solid wood base that also helps a bit.
Those of use that like the vintage gear do get a little off base when talking about new gear to be the equal to what we know and love. No problem, I'm there, too. The Magnepan Unitrac is the equal of arms up to about 1500. Haven't proven it, but with the right cartridge, that might go higher.