Humminbird XNT 9 DB 74 T Installation Manual page 3

TRANSOM TRANSDUCER Installation Guide
3. Refer to the minimum clearance requirement between the bottom of the bracket and the
bottom of the transom for your boat type below:
1/4" (6 mm) clearance for fiberglass boats
1/8" (3 mm) clearance for aluminum boats
NOTE FOR ALUMINUM BOATS: For flat-bottomed aluminum boats, some additional
adjustment may be needed to accommodate the rivets on the bottom of the boat (the gap
may need to be a little smaller than 1/8"). This will help you to avoid excessive turbulence at
high speeds.
If your propeller moves clockwise, mount the transducer on the starboard side, and align the
bottom right corner of the mounting bracket with the bottom of the boat. If your propeller
moves counterclockwise, mount the transducer on the port side, and align the bottom left
corner of the mounting bracket with the bottom of the boat.
4. Continue to hold the bracket on the transom of the boat, and use a pencil or marker to mark
the two initial drill holes (see Using the Mounting Bracket to Mark the Initial Drill Holes). Mark
the drill holes near the top of each slot, making sure that your mark is centered in the slot.
NOTE: The third hole should not be drilled until the angle and height of the transducer is finalized,
which you will not do until a later procedure.
5. Confirm that the drill bit is perpendicular to the actual surface of the transom, (NOT parallel
to the ground), before you drill. Using a 5/32" (4 mm) bit, drill the two holes only to a depth of
approximately 1" (25.4 mm).
NOTE FOR FIBERGLASS HULLS: It is best to start with a smaller bit and use progressively
larger drill bits to reduce the chance of chipping or flaking the outer fiberglass coating.
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| Assemble the Transducer and Initial Mounting
In this procedure, you will assemble the transducer using the hardware provided, then mount it and
make adjustments to its position without locking it in place.
1a. If your transom is angled at 14 degrees (a common transom angle for many boats), use
position 1 for the ratchets.
1b. If you have a different transom angle or do not know your transom angle, refer to the
Transducer Installation Resource Guide on our Web site at humminbird.com for detailed
instructions.
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 (see Installing the Ratchets in
Position 1). 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.
3. Hold the ratchets on the transducer knuckle until it snaps into place with the other hand. Refer
to the illustration Fitting the Pivot Arm over the Ratchet .
4. P ut the pivot bolt through the assembly to hold it in position and loosely install the nut, but do
NOT tighten the nut at this time (see Inserting the Pivot Bolt).
CAUTION! Do not use a high speed driver on this combination of fasteners. Hand-tighten only.
5. Insert the pivot arm assembly into the mounting bracket (see Inserting the Pivot Arm Assembly
into the Mounting Bracket). Do NOT snap the assembly closed, as you will need to access the
mounting bracket in the next step.
532314-3_B
Installing the Ratchets in Position 1
knuckle
rib at
position 1
bead
Fitting the Pivot Arm
over the Ratchet
Inserting the Pivot Bolt
Inserting the Pivot Arm Assembly
into the Mounting Bracket
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ratchet