Humminbird 917C Installation And Operation Manual page 24

2. Place the two ratchets, one on either side of the transducer knuckle,
so that the beads on each ratchet line up with the desired position
number on the knuckle. If you are setting the ratchets at position 1,
the beads on each ratchet will line up with the rib on the transducer
knuckle to form one continuous line on the assembly.
NOTE: The ratchets are keyed; make sure that the square teeth on each ratchet face
the square teeth on the transducer knuckle, and the triangular teeth face outward.
Hold the ratchets on the transducer knuckle with one hand and fit
the pivot arm over them until it snaps into place with the other
hand. Refer to the illustration.
Measuring the Transom Angle
Plumb
line
Transom
Angle in
degrees
(°)
Measured
Distance (X)
12"
Weight
Transducer Knuckle Positions
Ratchets Placed in Position 2
Bead
Rib
16
Ratchets Placed in Position 1
Knuckle
Rib at
position 1
Fitting the Pivot Arm Over the Ratchet
Ratchet
Beads
Ratchet