Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 312Get this manual
POWER TRIM
TRIMMING OUTBOARD "DOWN" (IN):
WARNING
Excessive speed at minimum trim "In" may result in undesirable andor unsafe steering conditionsTest for handling characteristics after any adjustment is made to the trim angle (and tilt pin location)Aids planing, particularly with heavy loadsImproves ride in choppy water conditionsExcess trim "In" can cause "bow steer" (boat veers to left or right)Transfers steering torque to starboard (right)Improves acceleration to planing speedThe "Down" circuit actuates the down solenoid (under engine cowl) and closes the motor circuitThe electric motor drives the pump in the opposite direction as the up circuit, forcing fluid thru passageways into the "down" side of the tilt ramThe tilt ram moves the engine down to the desired position
Trailering Outboard
The "Up" circuit first moves the trim cylinders; when the trim cylinders extend fully, the tilt ram extends to tilt the outboard to the full up position for traileringBefore the boat is trailered, the operator should check for clearance between the outboard skeg and pavement to prevent damage to skeg from striking pavementIf the outboard must be tilted for clearance between skeg and pavement, device such as "Transom Saver" should be installed to prevent stress to boat transom from outboard weight while the boatoutboard are being trailered