I recently completed my first restoration of my stationary R & M. Style #107990 ser. # 93222. It sat in my toolshed for many years and always ran fine in spite of the abuse. To make a long story short, it hasn't run the same since I got it back together. I had to repair the wires out of the stator, but was very careful, using solder & heat shrink. It will not self start, and once I help it, it runs for a few minutes starts slowing down, and then quits and just sits there and buzzes. Could my choice of lube be the problem??. I forgot to prelube the bearings when I put it together,but when I cleaned out the lube cups I put Marvel Mystery oil in them and saturated the wicks. I have heard about the "Purple" stuff should I have lubed with it or something like it?? Would appreciate your opinion, I'm learning as I go.
Try spinning the blade by hand with the power off. Does it spin multiple revolutions and gradually come to a rest? If not it could be miss-alignment of the front and rear bearing due to re-assemble. Try loosening the removable end of the motor slightly and seeing if that fixes the problem. (you might need to very slightly pry off the end of the motor case at varying positions until the binding goes away.)
If the fan spins freely manually, then you most likely have an electrical related problem. Does the fan act like it wants to start? Sometimes the electrical connection you made to the stator gets broken when the stator is pressed back into the motor case. (it's happened to me multiple times)
In addition, the stator might not be all the way into the motor case due to bunched up connections to lead wires. (again that's happened to me before) The stator must be seated all the way into the motor case and resting against the back of the motor case.
I doubt you have a lubrication problem. You probably either have a binding rotor or an electrical problem.
Does your R&M have a centrifical switch? That might also be the problem.