1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 228Get this manual
GEAR HOUSING
Gearcase Removal
WARNING
To prevent accidental engine starting, remove (and isolate) spark plug leads from spark plugs BEFORE removing gear housing1Remove and isolate spark plug leads from spark plugs2Shift outboard into FORWARD gear3Tilt outboard to full UP position4Remove shift shaft retainer