I tried a 15x1 needle and it worked perfectly. Finally got the tension adjusted...it was way off. It sews good but is VERY noisy. There is a rubber wheel that rests against the handcrank wheel (no belt) and it has a flat spot on it. I guess from sitting unused so long and I think that is what is making the noise. When I hold the motor away from the machine its quiet. Hopefully cleaning everything tomorrow will help too. The only vintage machines I've used before recently was my Grannie's and I've never seen one that doesn't need a belt. Was this a common thing?