Suzuki DF9,9 Service Manual page 206

8-20 LOWER UNIT
• If Reverse gear engages earlier than Forward, the turn-
buckle should be rotated clockwise.
2. Lock the upper nut securely against the turnbuckle when
clutch lever adjustment is correct.
GEAR OIL
Fill the gearcase with specified gear oil.
See the "PERIODIC MAINTENANCE/GEAR OIL" section on
page 2-5.
Necessary amount of gear oil:
 99000-22540: SUZUKI OUTBOARD MOTOR GEAR OIL
170 ml (5.7/6.0 US/lmp.oz)