Janome 7330 Servicing Manual page 5

CONDITION
6. Noisy 1. Backlash between shttle hook
operation gear and lower shaft gear is too
great.
2. Lower shaft gear is loose.
3. Inappropriatte belt tension.
4. Not enough oil.
1. Inappropriate feed balance.
7. Deformation
pattern
2. Inappropriate zigzag
synchronization.
3. Upper thread tension is too
strong.
CAUSE HOW TO FIX
See mechanical adjustment
"Backlash (lower shaft gear)".
Eliminate the looseness.
See part removal and replacement
"driving motor (DC motor)".
Oil all moving parts.
See mechanical adjustment
"Stretch stitch feed balance".
See mechanical adjustment
"Zigzag synchronization".
See mechanical adjustment
"Needle thread tension".
3
7330
REFERENCE
p. 14
p. 28
p. 36
p. 18
p. 16
p. 17