Yamaha F50D Servise Manual page 224

LOWR
9. Install the special service tools 7, 8, 9,
and put another special service tool 0
on the handle stopper 6 to apply load.
9
7
Magnet base plate 7: 90890-07003
Dial gauge set 8: 90890-01252
Magnet base 9: 90890-06844
Pinion height gauge set 0: 90890-06668
10. Slowly turn the drive shaft clockwise and
counterclockwise, and then measure the
backlash at the position where it stops in
each direction.
TIP:
Do not turn the drive shaft with excessive
force, otherwise the forward gear will rotate,
leading to incorrect measurements.
11. Turn the drive shaft 180° clockwise and
measure the backlash again.
8-25
Lower unit
0
6
8
f
e
TIP:
Measure the backlash at 4 points: c, d,
9
e, and f, turning the drive shaft 180°
clockwise after each measurement. Note
the measurement data in the shimming
check sheet.
9 When turning the drive shaft, hold it with a
little force. A knocking sound may be heard
when the drive shaft is rotated, but this is
the sound of the pinion contacting the
reverse gear and does not affect the back-
lash measurement.
12. Determine the backlash average, and
then truncate it by dropping the numbers
after the 1/100 place without rounding.
Example:
Measurement
0.30
point c
Measurement
0.35
point d
Measurement
0.31
point e
Measurement
0.36
point f
Average 0.3300
Truncated
0.33
average (BL1)
c
d
(mm)
0.29 0.30
0.32 0.36
0.34 0.34
0.35 0.33
0.3250 0.3325
0.32 0.33