1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 243Get this manual
CLAMPSWIVEL BRACKETSDRIVE SHAFT HOUSING
20Shift to forward gear21Assemble supplied reverse hook guide around lower shift shaft and tighten boltnut to allow adjustment22Lift and hold reverse lock hook in the full up position23Slide reverse hook guide up shift shaft to make contact with loop of reverse lock link rodDO NOT bend link rodTighten guide boltnut to torque of 50 lbin(5.7 Nm)
a-Reverse Hook Guide b-BoltNutTorque to 50 lbin(5.7 Nm) c-Reverse Lock Hook Link Rod d-Reverse Lock Hook 24Lower outboard to the normal operating position25Check reverse lock operation as follows: Forward Gear Reverse lock fully releasedOutboard will tilt upNeutral Reverse lock engagedOutboard will not tilt upReverse Gear Reverse lock fully engagedOutboard will not tilt up