Humminbird HDR 400G, HDR 400I User Manual

GUARANTEED DEPTH PERFORMANCE
Your Humminbird Digital is guaranteed to operate to 400 feet when the unit and transducer are

properly installed, following the instructions in this operations manual.
It cannot be emphasized enough how important it is to correctly install the unit and transducer.

Improper installation will void the depth guarantee because it can degrade the unit’s
performance.

TRANSDUCER MOUNTING PROCEDURE
Humminbird’s high-speed transducer is supplied with your LCR. This transducer has been

designed to give good high speed readings on most all boat designs, including aluminum.
Please carefully consider the following before installing your transducer.

TRANSDUCER MOUNTING OPTIONS
A. Transom Mount - The Humminbird high speed transducer allows the transducer element to be

mounted below the bottom of the boat hull keeping the transducer out of turbulent water and
insuring good high speed operation. The transducer will abs orb the blow of any obstruction

by rotating up out of the metal spring bracket without harming the transducer, or your boat.
The transducer can be re-engaged by simply rotating the transducer down and snapping it
back in place. (See Figure A)

B. Inside Hull Mount - The high speed transducer can be mounted inside the hull (without pivot

assembly) using the proper two-part epoxy, such as Humminbird’s epoxy kit. Even though
there is some loss of signal in shooting through the hull, your LCR will perform well with this
type of installation. You cannot shoot through the hull of an aluminum boat.

C. Trolling motor Mount - This type of transducer is not supplied with your LCR. It is designed to

mount on the foot of a trolling motor. You may exchange your un-used high speed
transducer for a trolling motor transducer. Call the Humminbird Customer Service
Department.

D. Bronz Thru-Hull Mount - This transducer is not supplied with your LCR but for an additional

cost you may exchange your un-used high speed transducer for a bronz thru-hull. The bronz
thru-hull transducer has a threaded stem which installs through a hole drilled in the boat hull,
leaving the housing exposed under the boat. This type of installation must be used for many
boats with in-board engines, because there is no suitable location on the transom away from
the noise and turbulence created by the prop. A bronz thru-hull transducer should be installed
by qualified personnel only.
The LCR will operate well at high speeds with a properly mounted transducer. Remember, a
transducer will not work transmitting through air or through air bubbles.

1. TRANSOM MOUNTING PROCEDURE

Step 1.
MOUNTING LOCATION- It is important that the transducer be mounted on the transom where
water flow is in constant contact with the trans ducer. You may wish to observe the rear of the
boat while it is moving through the water to determine the best mounting location.

Step 2.
BRACKET INSTALLATION (Aluminum Boats)- To install the metal bracket on an aluminum boat
locate the template on the transom between rows of rivets, or ribs that are on the bottom of the
boat. Align the template so that the bottom corner of the template nearest the center of the
transom is on the bottom edge of the transom.

Once the location is determined mark and drill three 7/64” dia.. holes noted on the template.
Attach the metal bracket using three #10 self threading screws supplied. Be sure to align holes in
the center of the
Bracket slots. On some aluminum boats it may be necessary to use a wood back-up plate. It is
important to use a silicone sealant between the screwhead and bracket in order to prevent
leaking. (See Figure C)

Step 2.
BRACKET INSTALLATION (Fiberglass Boats)- If your boat has a stepped transom located
below and under the main transom, the compact transducer design allows mounting in this area.
This mounting location is recommended for good reading at very high speeds. (See Figure D)

To install the metal bracket on a fiberglass boat, locate the template on the transom in the same
manner as for an aluminum boat. (See Figure C)

NOTE: On boats with more than 15 degree deadrise angle it may be necessary to mount the
transducer slightly off parallel with the water level. (See Figure E)

Mark and drill the three 9/64” dia. holes as shown on the template. Attach the metal bracket using
the three #10 self threading screws supplied. Be sure to align the holes so that they are centered
vertically in the three slots found in the bracket. It is important to use a silicone sealant between
the screwhead and bracket in order to prevent leaking.

Step 3.
TRANSDUCER PIVOT ASSEMBLY - Assemble the pivot to the transducer main body using the
two ¼”x5/8” allen head screws, two 3/8” tooth washers and two, ¼” square nuts. Make sure the
tooth washers are sandwiched between the transducer main body and the pivot. The square nuts
are trapped inside the pivot and will not rotate as the allen head screws are tightened.
HOWEVER, DO NOT TIGHTEN AT THIS POINT. (See Figure F)