2001 Mercury Mariner 50-60HP Factory Service Manual, Page 47Get this manual
GENERAL INFORMATION
Power Trim System
General Information
The power trim system is filled at the manufacturer and is ready for useTrim outboard through entire trim and tilt range several times to remove any air from the systemThe trim system is pressurized and is not externally vented
Power Trim Operation
With most boats, operating around the middle of the "trim" range will give satisfactory resultsHowever, to take full advantage of the trimming capability there may be times when you choose to trim your outboard all the way in or outAlong with an improvement in some performance aspects comes greater responsibility for the operator, and this is being aware of some potential control hazardsThe most significant control hazard is pull or "torque" that can be felt on the steering wheel or tiller handleThis steering torque results from the outboard being trimmed so that the propeller shaft is not parallel to the water surface