Humminbird 997c SI Combo, Installation And Operation Manual

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To mount the transducer pivot assembly to the bracket:
1. Slide the assembled transducer into the metal bracket from the
bottom, aligning the large hole at the top of the bracket with the
hole in the pivot.
2. Insert the headed pin through the pivot holes in the bracket and
pivot. The headed pin can be inserted from either side of the
bracket.
3. Place the nylon washer over the opposite end of the headed pin.
Place the stainless washer over the 1/4"-20 x 5/8" (16 mm) screw
threads, then insert into the opposite end of the headed pin and
finger tighten only. The screw has a thread locking compound on the
threads to prevent loosening, and should not be fully tightened until
all adjustments are made.
NOTE: The running position of the transducer is now completely adjustable.
Subsequent adjustment may be necessary to tweak the installation after high
speed testing.
To adjust the running position of the transducer:
The transducer mounting bracket allows height and tilt adjustment, while
the pivot bolt allows angular adjustment. These adjustments will help
reduce cavitation. Initially, adjust the transducer as described in the
following paragraphs. Further adjustment may be necessary to refine the
installation after high-speed testing.
1. First, adjust the pivot angle of the transducer body, so it is parallel
with the length of the hull of the boat.
2. Fully tighten the two pivot screws, using the supplied Allen wrench.
Access to the pivot screws is provided by the lower holes in the side
of the mounting bracket. It may be necessary to re-tighten the pivot
bolt after initial use as the plastic may still be conforming to the
pressure from the lock washers.
Normal Cavitation Cavitation that will cause
erratic sonar readings
Screw 1
Headed Pin
2
Allen Wrench
3
Nylon Washer
4
Stainless Washer
5
3
1
5
4
2
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