Mercury Mariner 4, 5 102CC Sail 1990 Outboard Service Shop Manual, Page 88Get this manual
Draining and Inspecting Gear Housing Lubricant 1Remove "O IL" (fillplug (a) and "OIL LEVEL" (vent) plug (b) Let gea housing lubricant drain into lea drain pan
Propeller Removal
-'l.WARNING
To prevent accidental engine starting remove and isolate spark plug lead from spark plug before removing gear housingplace block of wood between the antiventilation plate and propellerto protect hands from propeller blades while turning propeller nut1Remove cotter pin (a),2 11 24 21 133
2Inspec lubricant for metal particlesPresence of small amount of fine particles (resembling powder) indicates normal wearPresence of larger particles or large quantity of fine particles indicates need for gear housing disassembl and component in-