Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 230Get this manual
Removal, Disassembly, Cleaning and Inspection of Counter Rotating Gear Housing REMOVAL
AWARNING
Disconnect high tension leads from spark plugs and remove spark plugs from engine before removing gear housing from drive shaft housing
ACAUTION
Gear housing MUST BE in neutral position and shift shaft MUST BE removed BEFORE propeller shaft can be removed from gear housing1Disconnect high tension leads from spark plugs and remove spark plugs from engine_ _J 24S91