I had a FW that the belt was broke. I purchased the Singer 194144 belt to get her back in operation. Immediately after installing, I noticed that the motor sound was different and the speed was gone. It was like someone had put a governor on it! I took an original belt off another FW and the sound was back to normal as was the speed.
I stopped in at a local Singer repair shop to see why this was happening. The tech told me that is what to expect, with a new belt, it slows the machines down, some more than others. He said he didn't know of any other belts for the FW to try.
While I've not read every post in the vintage forum, I don't recall reading anyone else expressing this concern. Are you all still using the original belts so you've not experienced this? Or are there others like me that have had to use a new belt and are now having speed issues?
At the time we ordered spare bits for the FW kids, we got like a half a dozen belts. I'm thinking we've wasted money. I use my 1934 FW daily and she flys. I can't imagine her just plugging along. I see Sew Classic has a 221 belt that has lugs and maybe it is more flexible? Anyone here bought that one? I may just have to try that and see if it's better. I worry if the gear ratio or whatever you call this issue is is off, then maybe it will burn up my motors using the new "original" belts.
Here's the "lug" belt link - http://shop.sew-classic.com/Belt-171...221-1712LT.htm