T R O U B L E A N D CAUSE
C O R R E C T I O N
Refer t o :
I N S T R U C T I O N
or:
13.
U N E V E N SEAMS OF REVERSE PATTERNS
Refer t o : SERVICE M A N U A L
No.)
following models
( 1
Improper setting o f reverse feed devices
9-1
10-1
10-2
14.
BREAKING OF UPPER T H R E A D
( 1 Incorrect relation o f needle
thread
( 2 ) Bent or b l u n t needle
( 3 ) Inferior needle eye
( 4 ) Incorrect threading
Inferior needle slot o f needle plate
( 6 ) Upper thread tension t o o tight
( 7 )
Scratch on the shuttle hook
Relative chart
Change the needle
Change the needle
Upper threading
Change needle plate
Thread tension
Change the shuttle hook
15. BREAKING LOWER T H R E A D
( 1 N o t smooth running o f bobbin
Scratch o n tension spring o f bobbin case
Scratch o n the shuttle hook
Lower thread tension t o o tight
Change the bobbin
Change the spring
Change the shuttle hook
Thread tension
