9. TROUBLESHOOTING
BAS-326H-484, BAS-326H-484 SF
58
Problem Cause
Remedy
Reference
Needle is too thin.
Select a needle that is suitable for the
sewing conditions.
P. 28
Hole diameter in needle hole plate is
too small.
Replace the needle hole plate with one
with a larger hole diameter.
Feed plate is too thin.
Use a thicker feed plate.
*Recommended thickness: 1.5 mm
Hole diameter of intermittent presser
foot is too small.
(-484 SF specifications only)
Replace the intermittent presser foot
with one with a larger hole diameter.
Sliding parts of outer rotary hook and
inner hook have little or no sewing
machine oil.
Lubricate the felts for the sliding parts
of the outer rotary hook and inner hook.
P. 21
Damage or burring in parts such as the
rotary hook, hook stopper, needle hole
plate, needle or thread path.
Repair the respective part by buffing it.
Alternatively, replace the part.
*
Lower thread tension is too strong.
Reduce the lower thread tension.
P. 28
Upper thread tension is too weak.
Increase the upper thread tension.
*Adjust the upper thread tension after
adjusting the lower thread tension.
P. 29
Thread take-up spring tension is too
weak.
Increase the tension of the thread
take-up spring.
P. 36
Upper thread does not release
correctly from hook stopper.
Adjust the forward-back clearance
between the tip of the hook stopper
and the surface of the inner hook
needle drop section to approximately
0.8 mm.
P. 38
Feed timing is too fast.
Retard the feed timing.
*
Upper thread is not
tight.
Intermittent height of intermittent
presser foot is too low.
(-484 SF specifications only)
Adjust the intermittent height of the
intermittent presser foot.
(*1)
Lower thread tension is too weak.
Increase the lower thread tension.
P. 28
Lower thread is not
tight.
Upper thread tension is too strong.
Reduce the upper thread tension.
*Adjust the upper thread tension after
adjusting the lower thread tension.
P. 29
Uneven thread
tightening at the sewing
start.
Bobbin spinning.
Use an anti-spin spring.
P. 28
Adjust the sub-tension so that the
upper thread trailing length after thread
trimming is approximately 45 mm.
P. 29
Poor seam finish on
underside of material at
the sewing start.
Upper thread trailing length is too long.
Reduce the stroke of the thread
take-up lever.
* Adjusting the stroke of the thread
take-up lever should be carried out
also if adjusting the sub-tension fails
to improve the seam finish.
P. 38
Movable knife is blunt.
Replace the movable knife with a new
one.
P. 39
Fixed knife is blunt.
Sharpen the fixed knife or replace it
with a new one.
P. 39
Sub-tension is too weak.
Adjust the sub-tension.
P. 29
Upper thread trailing
length is irregular.
Thread take-up spring tension is too
weak.
Increase the tension of the thread
take-up spring.
P. 36
0574M
0573M
