CONSEW 206RB-5 THREAD SHREDDING ISSUE

[Mrrattle]

I bought my 206rb-5 used, was a mess, someone had used plastic shims under the feed dogs--obviously they didnt know how to adjust anything.

so i have gone through all the adjustments, as per manual and also a couple youtube videos by mtrc (very good videos by the way)

anyway, it sews pretty good now at low speed, but as soon as i go fast the thread shreds, tried different thread and needles. running #20 needle with 92 thread.

one this i noticed the needle is contacting the bobbin cage pretty hard, the hook has clearance (enough for one piece of paper).

question is, is this normal contact or has someone filed the hook down so much it has created other clearance issues?

[Gump]

No this is not normal. Check that the latch is clicking when you put the bobbin case in place, and if not check for debris or plastic shims! Also check that the bobbin is sitting flush in the bobbin case, and that it is the right bobbin for the machine. Your hook should be even with the plate screwed on just about on top of the hook. Lastly, are the needles 135 x 17 size?

[nylonRigging]

Sounds like the machine was misused and monkey mechaniced  by the previous  owner . If all is in time properly . The going Slow is Fine, and the Fast RPM is Bad on thread could also mean simple problems .
Maybe some needle strikes. Check real close for a Burr or a Nick in your Needle-Plate, smooth-out with fine emery . Check for Burr in the Hook, take piece of cotton ball or Q tip and run it across Hook. If any snagging, smooth it out.
In my  life I have even run across/pulled-out a couple new Needles out of the Pack also that had a 'sharp Eye' inside-edge that would also shred Thread .
.

[Mrrattle]

Got it sorted, new hook assembly, previous owner had definitely filed hook way down..was missing about 1mm of metal. I have never seen something so bodged before. Sad thing is the person I bought it from had both manuals so they had no excuse to make such a mess. Golden rule applies..anything used assume everything is wrong.