Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 313Get this manual
POWER TRIM
Trim "In" Angle Adjustment
WARNING
Boat operation with outboard trimmed to the full "In" trim angle [not using the trim angle adjustment bolt] at planing speed may result in undesirable andor unsafe steering conditionsA water test for handlingsteering conditions is required after any trim angle adjustmentsIMPORTANT: Some boatmotor combinations not using the trim angle adjustment pin and trimmed to the full "In" trim angle position may not exhibit any undesirable andor unsafe handling andor steering characteristics at planing speedIf so, not using the trim angle adjustment bolt may be advantageous to acceleration and planingA water test is required to determine if these characteristics apply to particular boatmotor combination