Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 347Get this manual
eAfter installation is complete (and before operating outboard(s)check that boat will turn right when steering wheel is turned right and that boat will turn left when steering wheel is turned leftCheck steering thru full range (left and right) at all tilt angles to assure interference-free movementAdjust trim tabs of both outboards, as outlined in "Trim Tab Adjustment," following Operate boat perCheck trim tab position as fOllOWS," precedingto check trim tab settingReadjust trim tabs, if necessary
Ride Guide Steering Attachment Extension Couplers
Outboard Center Line Distance Required Coupler(s) Between Steering Eyes
Trim Tab Adjustment
DUAL OUTBOARD COUNTER ROTATION INSTALLATION 123Shift outboard into neutral and make sure ignition key is at positionRemove plastic cap from rear of drive shaft housing and loosen bolt and trim tabPosition trim tabs of both outboards straight to rear of outboard, so that tabs are aligned with gear housing center lineTighten both trim tab bolts securely and replace plastic capsNo further adjustment will be required