1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 326Get this manual
BIG FOOT
11Lift and hold reverse lock hook in the full up position12Slide 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 lb-in(5.7 Nm)a-Reverse Hook Guide b-BoltNutTorque to 50 lb-in(5.7 Nm) c-Reverse Lock Hook Link Rod d-Reverse Lock Hook 13Lower outboard to the normal operating position14Check reverse lock operation as follows: Forward GearReverse lock fully releasedOutboard will tilt upNeutralReverse lock engagedOutboard will not tilt upReverse GearReverse lock fully engagedOutboard will not tilt up