Janome MC9900 Service Manual page 17

Fig. 5
Hook base plate
Setscrew A
Setscrew C
Setscrew B
Adjustment 2
1. Remove the base cover and bed cover (see page 3
and 4).
2. Loosen the setscrews A and B.
Loosen the setscrew C just enough to move the hook
base plate (see fig. 5).
3. Turn the handwheel toward you.
Adjust the clearance between the needle and the tip
of the rotary hook by moving the hook base plate up
or down between -0.1and +0.05 mm at the both left
and right needle position (see page 14).
4. Tightent the setscrews A, B and C.
Check the following parts after this adjustment.
• Check the backlash between the lower shaft gear and
the hook drive gear. If the backlash is too great or the
engagement of the gears is too tight, adjust the
backlash (see page 16).
• Check the hook adjustment and needle bar height
after this adjustment (see page 18 and 19)
15