Yamaha 250GETO Service Manual page 199

4. Install the backlash indicator onto the
drive shaft (22.4 mm [0.88 in] in diame-
ter), then the dial gauge onto the lower
unit.
5. Set the lower unit upside down.
NOTE:
Install the dial gauge so that the plunger a
contacts the mark b on the backlash indica-
tor.
Backlash indicator 4: 90890-06706
Magnet base plate 5: 90890-07003
Dial gauge set 6: 90890-01252
Magnet base B 7: 90890-06844
6. Slowly turn the drive shaft clockwise and
counterclockwise, and measure the
backlash when the drive shaft stops in
each direction.
Forward gear backlash:
0.32 – 0.52 mm
(0.0126–0.0205 in)
6S35H11
Shimming (counter rotation model)/Backlash (counter rotation model)
7. Add or remove shim(s) if out of specifica-
tion.
Forward gear
backlash
Less than
0.32 mm (0.0126 in)
More than
0.52 mm (0.0205 in)
M: Measurement
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40 and
0.50 mm
8. Remove the special service tools from
the propeller shaft.
9. Turn the shift rod into the reverse position
c with the shift rod push arm.
Shift rod push arm:
90890-06052
10. Turn the drive shaft clockwise until the
dog clutch 8 is fully engaged.
8
c
Shim thickness
To be decreased by
(0.42 – M) × 0.78
To be increased by
(M – 0.42) × 0.78
6S360510
6-62
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