1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 46Get this manual
OUTBOARD INSTALLATION
Steering Link Rod Installation
IMPORTANT: The steering link rod that connects the steering cable to the engine must be fastened using special self locking nutsThese locknuts must never be replaced with common nuts (non-locking) as they will work loose and vibrate off freeing the link rod to disengage
WARNING
Disengagement of steering link rod can result in the boat taking full, sudden, sharp turnThis potentially violent action can cause occupants to be thrown overboard exposing them to serious injury or death
WARNING