1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 308Get this manual
Improves planing speed acceleration (by moving tilt bolt one hole closer to transom)Operating "Down" circuit will actuate the "down" relay (located under engine cowl) and close the electric motor circuit (motor will run in opposite direction of the "Up" circuit)The electric motor will drive the pump, forcing fluid thru internal passageways into the "down" side of the tilt ramThe tilt ram will move the engine down to the desired angle Trim "In" Angle Adjustment WARNING
Operating some boats with engine trimmed to the full "in" trim angle [not using trim adjustment bolt] at planing speed will cause undesirable andor unsafe steering conditionsEach boat must be water tested for handling characteristics after engine installation and after any trim adjustmentsIMPORTANT: Some boatmotor combinations, that do not use the trim adjustment bolt and are trimmed to the full "in" trim angle, will not experience any undesirable andor unsafe steering conditions during planing speedThus, not using trim adjustment bolt may be desiredHowever, some boats with engine trimmed to the full "in" trim angle at planing speed will cause undesirable andor unsafe steering conditionsIf these steering conditions are experienced, under no circumstances should the engine be operated without the trim adjustment bolt and without the bolt adjusted in the proper holes to prevent unsafe handling characteristicsWater test the boat not using the trim adjustment boltIf undesirable andor unsafe steering conditions are experienced (boat runs with nose down), install trim adjustment bolt in proper hole to prevent unsafe handling characteristics