Humminbird XTH 9 DB 74 P Guide D'installation page 3

PLASTIC THRU-HULL TRANSDUCER Installation Guide
apply marine adhesive
sealant to all mating
1. From the outside of the hull, drill a small pilot hole (smaller than the centering bit of your drill
bit or hole saw), at the mounting location you selected in section 2. Drill the hole perpendicular
to the hull.
2. Use the pilot hole (from the outside of the hull) to drill a 1 1/8" (2.8 cm) hole that is sized to fit
the threaded stem of the transducer. Drill the hole perpendicular to the hull.
3. Thoroughly clean and deburr the drilled hole and clean the outside of the hull.
4. The leveling block will be installed (uncut) on the outside of the hull. Proceed to section
4: Attach the Transducer.
Alternate Installation (Deadrise more than 8°):
For an installation where the deadrise is more than 8 degrees, use the included leveling block, cut
at the appropriate angle, to compensate for the deadrise.
1. From the outside of the hull, drill a small pilot hole (smaller than the centering bit of your drill
bit or hole saw), at the mounting location you selected in section 2. Drill the hole perpendicular
to the waterline.
2. Use the pilot hole (from the outside of the hull) to drill a 1 1/8" (2.8 cm) hole that is sized to fit
the threaded stem of the transducer. Drill the hole perpendicular to the waterline.
3. Thoroughly clean and deburr the drilled hole and clean the outside of the hull.
4. Cut the leveling block into two equal pieces: one which mounts outside the hull and is shaped
to match the profile of the transducer, and one which mounts inside the hull and provides a
level surface for the fasteners.
Standard Installation
(Flat Hull)
surfaces
Alternate Installation
(Deadrise angle more than 8°)
1/8"
minimum
thickness
apply marine adhesive sealant
to all mating surfaces
leveling block
(can also be positioned
outside of the hull)
hull
cut-leveling blocks
hull
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