PFAFF 145 Top Tension Issue

[leatherito]

I have a Pfaff 145 H3.

I ran out of thread while sewing and had to refill a bobbin.

 

After rethreading my machine, everytime I sew after a few stitches my top thread gets stuck in my tension disc (The top thread becomes extremely tight - to the point where pulling on it makes it snap - and the stitches start to show the bottom thread on top).

 

I then have to rethread the top thread, then after a few more clean stitches, the top thread becomes tight and the issue persists. Ive attached a photo here of the tension disc. Nothing has been done to it or changed. I am not sure why this keeps happening now.

 

Any advice?

[AlZilla]

I'd take the tensioner apart and see if there's a burr or something else going on. Funny it would rear it's head right at a bobbin change, but it's worth a look. 

Another thought, make sure it's tight starting at the tensioner and not further along the thread path. Be sure where the problem starts.

[CowboyBob]

As far as it's backed off I really doubt the tension is the problem,my guess is look for it to be binding ( or getting caught) somewhere between the spool & machine.