Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 475Get this manual
STEERING LINK ROD INSTALLATION IMPORTANT: The steering link rod that connects the steering cable to the engine must be fastened using special washer head bolt ("a"Part Number 10-14000) and self locking nuts ("b""c" Part Number 11-34863)These locknuts must never be replaced with common nuts (non locking) as they will work loose and vibrate off freeing the link rod to disengage Maintenance Instructions
Maintenance inspection is owner's responsibility and must be performed at intervals specified, following:
Normal ServiceEvery 50 hrsof operation or 60 days (whichever comes first) Severe ServiceEvery 25 hrsof operation or 30 days (whichever comes first)