2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 274Get this manual
TRIM AND TILT TRIM SENDING UNIT ADJUSTMENT
TRIM SENDING UNIT ADJUSTMENT
The sending unit eccentric cam must be adjusted so that the gauge needle is aligned with the lowest gauge mark with the outboard trimmed all the way DOWN
WARNING
To avoid personal injury, do not adjust the sending unit eccentric cam while the engine is being tiltedWhen the outboard is trimmed all the way DOWN, the sending unit lever touches the eccentric cam just forward of the top of the cam at the contact pointLoosen cam screw and rotate eccentric cam to adjust full down gauge position: If the needle was above the lowest mark, move the thick part of the cam TOWARD the contact pointTighten the screw, and recheck the gauge reading If the needle was below the lowest mark, move the thick part of the cam AWAY from the contact pointTighten the screw, and recheck the gauge reading