It could easily be in need of more oil and grease. The gear driven motor might need a bit of tending too, as you know well, old grease can dry and gum up parts. There's a worm gear behind the hand wheel, and luckily lots of good information on this are available. Much the same for the parts taking oil too, keep on oiling and test sewing. The 15-91 is nice, it's many peoples favorite straight stitcher. It should take a general 15 case, a new replacement part should work. Make sure the tiny finger is in the "right place", they come in both 11 o'clock and 1 o'clock position, I'm not sure what your machine takes. The controllers might need some work, but it's usually about checking wiring and adjusting for speed; not slugishness in the movment. There are a few blog posts on how to service the old button bakelite controllers, they are quite good when sorted out. To sum it up; more of the same as mentioned before, but it's always is a bit different from machine to machine.

Mickey as usual since I got to this forum you have given some sound advice. I was and still really skeptical to pull the motor off but certainly if there is a gear box that grease is likely dried up and sticky.

This is probably the best video on the gear driven models like the 15-91 and 201-2, there are one or two others that are very detailed and good too. It's hopefully much more info than you need to get yours in nice condition. Among the pictures there should be something on how to get to the gears behind the hand wheel. You can use either a light teflon grease like Triflow or vaseline. Vaseline is recommended for the motor wicks, or maybe the special grease from the Featherweight shop. There are issues with the wicking action on modern synthetic greases and it's hard to find the original saponified grease Singer recommended other than huge bucket size for industrial purposes.

Rains tutorials are the best on the 'net. I wish he was still active on his blog. Vaseline is the way to go with these motors, it was recommended by Singer. I'm not convinced that the expensive "special" grease the FW shop has is anything more than Vaseline with an additive.

Cari

It as the first machine hubby got when I decided I wanted a machine to quilt for real. I'm not much for one with all the bells and whistles. I use it all the time, for everything! I do have a cheap one that does fancy stitches but I don't use often. I have another called rose? Not sure , lol sits in closet as I use the 15-91

Mickey,
thanks for that link. After seeing the gearbox configuration I don’t need to pull the motor to clean and grease the worm gear I only need to pull the hand wheel. It just makes the job slightly less time consuming. Also less chance of destroying anything else.

Quick update I pulled the hand wheel and the grease was dried to a consistency of paraffin wax. I haven’t finished cleaning it all out yet but I’m confident that will cure the sluggish issue. I took the controller apart and everything looks good inside. I pulled the motor brushes they also looked fabulous. Started some New Years libations so this story is to be continued.

Guilty as charged. A 15-91 was the first vintage machine that got me started. Now I have 3 including one centennial badged one and 3 99s, including one centennial badged one. Hoping to land a 201 yet! [ATTACH=CONFIG]606044[/ATTACH]

I got my first Singer about 10 years ago, a 1955 201-2. Last year I got a 15-91 and a 15-125 but they're still sitting on a shelf waiting for a spa day. And just recently was given a 301(my 4th one) and another 201-2. I'm not a Singer gal but they keep finding me.

Cari

I have one. Well, two. Good go-to for nearly anything.