Originally Posted by
Cari-in-Oly
I can't take credit for this, it's not my idea. I read it in the files of the Vintage Singer Yahoo group. The first 401 I bought was so loud and whiny I hated it so decided to give this a try and it worked.
Cari
I can vouch for this method. Be sparing with the oil (I used bar oil for a chainsaw because of its high viscosity); you can always add another drop later if the first application doesn't solve the whine. The trick is to be sparing so the oil won't run down into the motor.