Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 291Get this manual
1The trimOut" limit switch is pre-adjusted at the factory to maximum allowable travelWhen tri mmed tothis maximum trim angl e, some boat motorcombinations may exhibit undesirable handling characteristicsIf this condition is experiencedit will be necessa ry to readjust the trim "Out" limit switch to reduce the amount of trim travel2If trim "Out" adj ustment is necessary, loosen clamp and rotate switc as show nRetig hten lamp and retest boat at max imum trim ang le for handling quality speedThus, not using trim adjustment bolt may be desiredHowever, some boats with engine trimmed to the fullIn" trim angle at planing speeds 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 hotes to prevent unsafe handling characteristics The trim adjustment bo lt is installed when the engi ne is shi pped Water test the boat not using the trim adjustment boltIf undesi reable andor un safe steering conditions are experienced (boat runs with nose down)install trim adjustment bolt in proper holes to prevent unsafe handli ng characteristics