Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 307Get this manual
Ride-Guide Steering Attachment Extension Couplers Outboard Center Line Distance
18 in thru 22- 1 in(457mm thru 572mm)
Trim Tab Adjustment
DUAL OUTBOARD
1Check trim tab position as follows :
Required Coupler(s) Between Steering Eyes (Shown Below)
9 in(229mm) Coupler
22- 12 inthru 24-1in (572mm thru 622mm) 23- 1 inthru 27- 1 in(597mm thru 699mm) 26-12 inthru 30-12 in (673mm thru 755mm)
IMPORTANT: Initial trim tab setting for both outboards should be straight to rear of outboard, so that tabs are aligned with gear housing center lineRefer to "If necessary, adjust trim tab as follows," followingaOperate boat at normal cruise throttle setting and adjust trim to optimum setting bIf boat pulls to the right (starboard)tra iling edge of trim tab must be moved to the right (when viewing outboard from behind) If boat pulls to the left (port)trailing edge of trim tab must be moved to the left2If necessary, adjust trim tab as followsaShift outboard into neutral and make sure ig nition key is at "OFF" position Remove plastic cap from rear of drive shaft housing and loosen bolt and trim tab