Brother S-7300A Service Manual page 163

5. Loosen the two set screws (6) of timing pulley D (5).
0962D
6. Remove the four socket bolts (7), and then remove the
sewing machine motor (8).
0963D
7. Momentarily return the machine head to its original
position, and then loosen the two set screws (10) of the
tension pulley (9).
8. Turn the tension pulley (9) to loosen the belt tension.
0964D
S-7300A
8. REPLACING PARTS
152