Use high-quality white spindle oil (ISO VG 18 or 22).
This often occurs due to thread wrapping around the handwheel or the lower looper drive. Open the side cover and clear any debris. manual kingtex sh 6000 series hit verified
Capable of reaching up to 7,000–8,500 stitches per minute depending on the specific sub-model. Use high-quality white spindle oil (ISO VG 18 or 22)