Janome NH22 Service Manual page 5

CONDITION
6. NOISY 1. BACKLASH BETWEEN SEE
OPERATION SHUTTLE HOOK GEAR AND
LOWER SHAFT GEAR IS TOO
GREAT.
2. LOWER SHAFT GEAR IS
LOOSE.
3. INAPPROPRIATE BELT
TENSION.
4. UPPER SHAFT GEAR IS LOOSE.
5. NOT ENOUGH OIL.
7. DEFORMATION 1. INAPPROPRIATE ZIGZAG
PATTERN SYNCHRONIZATION.
2. INAPPROPRIATE
DISENGAGEMENT OF CAM
FOLLOWER.
3. UPPER THREAD TENSION
IS TOO STRONG.
WHAT TO DO WHEN
CAUSE
5
HOW TO FIX
MECHANICAL
ADjUSTMENT "CLEARANCE
BETWEEN NEEDLE AND
SHUTTLE (NO.2)".
ELIMINATE THE LOOSENESS.
SEE MECHANICAL
ADjUSTMENT "MOTOR BELT
TENSION".
ELIMINATE THE LOOSENESS.
OIL ALL MOVING PARTS.
SEE MECHANICAL
ADjUSTMENT "NEEDLE
SWING".
SEE MECHANICAL
ADjUSTMENT
"DISENGAGEMENT OF CAM
FOLLOWER".
ADjUST UPPER THREAD
TENSION CORRECTLY.
REFERENCE
P.14
P.22
P.11
P.21
P.8