It is necessary to adjust the thread tension for the seams shown below.
[ ADJUSTING THE NEEDLE THREAD TENSIONS ]
[ ADJUSTING THE LOOPER THREAD TENSIONS ]
The left needle thread tension is too loose.
The right needle thread tension is too loose.
The lower looper thread is tight and/or
the upper looper thread is loose.
The upper looper thread is tight and/or
the lower looper thread is loose.
Loosen the lower looper thread tension
and/or tighten the upper looper thread
tension.
Loosen the upper looper thread tension
and/or tighten the lower looper thread
tension.
Tighten the left needle thread tension.
Tighten the right needle thread tension.