1996 Johnson/Evinrude Outboards 25, 35 3-Cylinder Service Manual, Page 300Get this manual
Sending Unit Adjustment [] 1The sending unit eccentric cam must be adjusted so that the gauge needle is aligned with the lowest gauge mark with the motor trimmed all the way DOWN[]]2Check if the gauge needle is above or below the lowest gauge mark Tilt engine UP and engage trailering lock
&3To avoid personal injury, do not adjust the sending unit
eccentric cam while the engine is being tilted