Jack C4 - Adjustment of Upper Looper

6.Adjustment of upper looper：
When upper looper move to
highest piont，
The distance between looper tip
and left needle hole
Is 5.4-5.7mm（4 thread）、
4.5-5mm（5 thread），the height
from looper tip to needle plate
Is 11.5mm（4 thread）、10.5mm(3
thread、5 thread)。
5.4-5.7mm
11.5mm
Maintenance instructions