SINGER W7317 - Manual (Page 18)

16. CLEANING THE SNAP-OPEN-RACE
When the thread is tangled in the race or dust gets into the
race-way, this will cause abrupt heavy running or complete
stoppage of the machine.
If SO:-
1) Raise the needle bar to its highest position and take out
the bobbin case. ,
2) Snap-out knob (A) on both sides of shuttle race releases
to outside, then take out the outside-ring and the shuttle
hook with your fingers. IFig. 241.
3) After shuttle-race and shuttle-hook have been cleaned,
put all of them back in reverse order.
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