Mercury Force 9.9, 15HP Outboards Service Manual, Page 184Get this manual
HADJUSTING GEAR SHIFT 1Adjust lower gear shift rod
Shift into neutra l
NOTE: Raise or lower gear shift rod until you can rotate the driv8shaft without the propeller shaff rotating
Rotate lower gear shift rod until center
of hole is 3116 364 in(4.75 1.19 mm)
below top mounting su rface of upper gear housing