Toyota SL1A Manual page 19

FOUR THREAD OVEREDGING STITCH USING 2 NEEDLES
When the lower looper thread is unbalanced and appears on the top-side of fabric
Tighten the thread tension of the lower looper
(Dial R) or loosen the thread tension of the
upper looper (Dial B).
When the left-hand needle thread is too loose
Tighten the thread tension of the left needle
(Dial Y) or loosen both looper thread (Dial B
and R).
When the right-hand needle thread is too loose
Tighten the thread tension of the right needle
(Dial G).
Wrong side
Right side
Wrong side
Right side
Wrong side
Right side
1 -18
Lower looper thread
Right-hand needle
thread
Upper looper thread
Left-hand needle
thread
Lower looper thread
Right-hand needle
thread
Upper looper thread
Left-hand needle
thread
Lower looper thread
Right-hand needle
thread
Upper looper thread
Left-hand needle
thread