Originally Posted by ghostrider
When the foot is down, the tension discs are engaged and you are putting undue stress on the thread and the discs when you pull it to thread the needle. This is true for any sewing machine. I think your repair guy's explanation is right on and you should listen to him. I never thread machines with the foot down...it's like pushing a car with the brakes on. :D
Maybe this is why I have loose thread on the arm that goes up and down? I'll have to try threading with the foot up and see if this helps me - thanks!