Pfaff 145 sewing machine shredding top thread

I am not a professional upholsterer. But, I looked around for a while and saw a good deal on a pfaff 145 so I bought it. It's an amazing beast and just learning how to sew on it compared to my Kenmore homeboy model has been a bit of an adventure.

One problem I'm seeing is shredding of the top thread. The machine was out of adjustment where the hook was running too close to the needle and it was whacking itself out of hook timing. Both the hook timing adjustment and the needle to hook distance have been adjusted by the guy I bought it from who is not a machine repair dude but who has used that machine and others like it for over 40 years. With all that, here's what's going on...

When I sew, the machine runs smoothly and the stitch and tensions seem good. But, quite often (at least two or three times per bobbin) the top thread seems to get some of it's strands cut and those loos strands start to ball up where the thread goes through the needle bar guide. Since I know that hook smashed into the needle at least once (and probably about 4 times) I'm wondering if I might have created a burr on the hook or somewhere else that's slicing the thread strands. The tension on the thread is so high (compared to the home machine) that I'm guessing it would not take much to cut a strand of thread.

Any advice or things to look for that anyone might have would be helpful.

I plan to take it apart a bit tonight and start "feelin her up" a bit and sanding down any obvious burrs with 320 abrasive. Also, is it possible that I snapped off the very tip of the bobbin hook? How sharp should that be. Sharp as a pin point?

I run a Consew and a Seiko in my shop. At some time or the other both of them will strip the thread. There's a lot of reasons for this. When it happens, the first thing I do is replace the needle. Usually there's debris or a burr on the edge of the hole that is catching the thread. It's also possible that if you're running a big thread like 138 that you have too small of a hole in the needle. If these are checked and it still does it, you might try slightly rotating the needle in it's carrier. You can't go too far or the hook won't catch, but some turning can better line up the thread with the hole, easing the stress and thereby the shredding.

When you've been noticing the shredding, what material have you been sewing? I run into it sometimes when doing repairs on older boat covers. The material itself is stiff enough that it gets sharp edges around the hole punched by the needle and will skin any size thread goign through it.

I've crushed the needle down right on the feedog and it's knicked and goofy all around the opening. But the way it's built, I still rarely have any trouble wiht it or anything else down below.