Garmin Fishfinder 140 User manual

Fishfinder® 90/140
owner’s manual

© 2006 Garmin Ltd. or its subsidiaries
Garmin International, Inc.
1200 East 151st Street,
Olathe, Kansas 66062, U.S.A.
Tel. [phone] or 800/800.1020
Fax [phone]
Garmin (Europe) Ltd.
Unit 5, The Quadrangle
Abbey Park Industrial Estate
Romsey, SO51 9DL, U.K.
Tel. [phone]
Fax [phone]
Garmin Corporation
No. 68, Jangshu 2nd Road, Shijr, Taipei County,
Taiwan
Tel. [phone]
Fax [phone]
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of Garmin. Garmin hereby grants permission to download a single copy of this manual onto a hard drive or other
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Garmin® is a registered trademarks of Garmin Ltd. or its subsidiaries and may not be used without the express permission of Garmin.
January 2006 Part Number 190-00582-00 Rev. A Printed in Taiwan

Fishfinder 90/140 Owner’s Manual i
INTRODUCTION
INTRODUCTION
This manual contains information about the Garmin®
Fishfinder® 90 and the Garmin Fishfinder 140.
Product Registration
Help us better support you by completing our online
registration today! Have the serial number of your
Fishfinder ready, and connect to our Web site
(http://www.garmin.com). Click on Product
Registration.
Use this area to record the serial number (8-digit number
located on the back of the box). Keep your original sales
receipt in a safe place, or attach a copy inside the manual.
Serial Number: ___ ___ ___ ___ ___ ___ ___ ___
Contact Garmin
If you have difficulty while using your Fishfinder, or if
you have any questions, in the U.S.A. contact Garmin
Product Support by phone: [phone] or 800/800.1020,
Monday–Friday, 8 AM–5 PM Central Time; or go to
http://www.garmin.com/support/, and select Product
Support.
In Europe, contact Garmin (Europe) Ltd. at
44/0870.8501241.

ii Fishfinder 90/140 Owner’s Manual
INTRODUCTION
Caring for the Fishfinder
The Fishfinder case is constructed of high quality materials
and does not require user maintenance except cleaning.
Cleaning the Case
Clean the Fishfinder’s outer casing (except for the screen)
using a cloth dampened with a mild detergent solution, and
then wipe it dry. Avoid chemical cleaners and solvents that
may damage plastic components.
Cleaning the Screen
The Fishfinder screen should be cleaned using a soft, clean,
lint-free cloth and eyeglass cleaner. Apply the liquid to the
cloth, and then gently wipe the screen with the moistened
cloth.
WARNING: The Fishfinder screen is coated with a
special anti-reflective coating which is very sensitive
to skin oils, waxes, and abrasive cleaners. CLEANERS
CONTAINING AMMONIA WILL HARM THE ANTI-
REFLECTIVE COATING. It is very important to
clean the screen using an eyeglass lens cleaner which
is specified as safe for anti-reflective coatings and a
clean, lint-free cloth.
Storage
Do not store the Fishfinder where prolonged exposure to
temperature extremes may occur (such as in the trunk of a
car), because permanent damage may result.
Water Immersion
The Fishfinder is waterproof to IEC Standard 60529 IPX7.
It can withstand immersion in 1 meter of water for 30
minutes. Prolonged submersion can cause damage to the
Fishfinder. After submersion, be certain to wipe and air dry
the Fishfinder before reuse.

Fishfinder 90/140 Owner’s Manual iii
INTRODUCTION
TABLE OF CONTENTS
Introduction .............................................................. i
Product Registration ...................................................i
Contact Garmin ...........................................................i
Caring for the Fishfinder ...........................................ii
Cleaning the Case ...........................................................ii
Cleaning the Screen .........................................................ii
Storage .............................................................................ii
Water Immersion .............................................................ii
Warning ......................................................................iv
Getting Started ........................................................ 1
Understanding Sonar .................................................1
Understanding the Fishfinder Screen ...............................1
Understanding Transducer Coverage ............................... 2
Using Simulator Mode ...............................................3
Installing Your Fishfinder ...................................... 4
Installing the Transducer ...........................................5
Assembling the Transducer ............................................ 5
Mounting the Transducer on a Trolling Motor ................ 5
Mounting the Transducer on a Transom .......................... 6
Installing the Fishfinder Unit .....................................9
Selecting a Fishfinder Location ....................................... 9
Mounting the Bracket Assembly ..................................... 9
Installing the Unit on the Mount Bracket ...................... 10
Installing the Wiring Harness ..................................10
Testing the Transom Mount Installation .................11
Operating Your Fishfinder ................................... 12
Understanding Basic Functions .............................12
Using the Main Menu ...............................................13
Options and Settings ...................................................... 13
Using the Setup Menu ..............................................14
Options and Settings ...................................................... 14
Appendix ............................................................... 17
Specifications ...........................................................17
Fishfinder 90 .................................................................. 17
Fishfinder 140 ................................................................ 17
Fishfinder 90 and Fishfinder 140 ................................... 17
Optional Accessories ...............................................17
Software License Agreement ..................................18
Limited Warranty ......................................................18
Index ...................................................................... 20

iv Fishfinder 90/140 Owner’s Manual
INTRODUCTION
Warning
This product, its packaging, and its components contain chemicals known to the State of California to cause cancer, birth defects, or
reproductive harm. This Notice is being provided in accordance with California’s Proposition 65. If you have any questions or would like
additional information, please refer to our Web site at http://www.garmin.com/prop65.

Fishfinder 90/140 Owner’s Manual 1
GETTING STARTED
GETTING STARTED
To get the most out of your new Fishfinder:
• Before you install and use your Fishfinder, read and
learn the information in this manual.
• Assemble and install the hardware (page 4).
• Practice using your Fishfinder in simulator mode
(page 3).
• Use the Fishfinder (page 12).
Understanding Sonar
The transducer that you mount on your vessel sends
sound waves toward the bottom of the water in a cone-
shaped pattern. When a sound wave strikes an underwater
object (such as the bottom, a structure, or a fish), sound is
reflected back to the transducer. The transducer collects the
reflected sound waves and sends the data to the Fishfinder
to be processed and shown on the screen. The underwater
data is shown on the screen in the order that it is returned;
the first returned is the first on the screen.
Generally speaking, if the only thing between the
transducer and the bottom is water, the first strong return
comes from the bottom directly below the transducer,
and this sets the bottom level. Weaker secondary returns
provide the detailed data. Stronger returns appear in darker
hues.
Understanding the Fishfinder Screen
The transducer sends a beam down to the bottom of the
water, much like the beam of a flashlight. The beam starts
small near your vessel and expands as it gets to the bottom.
The Fishfinder screen does not display a three-dimensional
representation of the underwater environment; the screen
is in two dimensions, much like if you took a picture
of an aquarium. Only the depth of the item in the water
appears. The screen does not show you where an item is
located horizontally in the water, as shown in the following
drawings. The fish is not directly above the tree in reality,
but it might look like it is on the Fishfinder screen.

2 Fishfinder 90/140 Owner’s Manual
GETTING STARTED
20'
10'
1'
Aerial View of the Water Sonar Display
Fish
Tree
Tree
Understanding Transducer Coverage
The bottom area covered by the transmitted sound waves
is determined by the beam width of the transducer and the
water depth. The Fishfinder can transmit either a narrow or
wide beam.
The narrow beam provides crisp bottom and structure
detail, but the coverage area is limited. As shown in the
following illustration, at a 30-foot depth, the narrow beam
covers the area of a 6-foot circle.
The wide beam covers a much larger area, but with some
loss of bottom and structure detail. In the following
illustration, at a 30-foot depth, the wide beam covers the
area of a 20-foot circle.
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

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
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
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Wide Beam Narrow Beam
Depth
Coverage
Diameter

Fishfinder 90/140 Owner’s Manual 3
GETTING STARTED
Using Simulator Mode
Use simulator mode to practice and learn the operation of
the Fishfinder. If the Fishfinder does not detect a transducer
at startup, it automatically starts in simulator mode.
While in simulator mode, the Fishfinder displays a bottom
scene, and you can control the Fishfinder (except the Gain
and Auto Gain options) just as if it were on the water.
If no keys are pressed for two minutes, the Fishfinder
automatically resets to default settings while in simulator
mode.
To exit simulator mode, turn off the Fishfinder.
Water depth Depth range
Water
temperature at
the transducer
Bottom shape and type
Structure
You see fish
as arches or
fish symbols in
three sizes.
Simulator mode
indicator

4 Fishfinder 90/140 Owner’s Manual
INSTALLING YOUR FISHFINDER
INSTALLING YOUR FISHFINDER
Make sure you completely read and understand all
instructions before you install and use your Fishfinder. If
you have problems, contact Product Support, or seek other
professional assistance.
You can install the Fishfinder hardware on a transom or on
a trolling motor. Before installation, make sure the wiring
harness can reach the Fishfinder and transducer locations.
Check the packing list below. If you are missing any items,
contact your Garmin dealer.
Packing List (one of each, unless otherwise noted):
A—Fishfinder sonar unit
B1—Swivel mount bracket
(Fishfinder 140; optional for
Fishfinder 90); or B2—Tilt mount
bracket (Fishfinder 90)
C—Swivel base (Fishfinder 140)
D—Mounting knobs
E—Mounting knob spacer
F—Snap ring
G—Transducer with power cable
H—Transducer mount
I—Trolling motor mount gasket
J—5 mm Flat washers (2)
K—5 x 30 mm Screws (2)
L—10-32 Lock nut
M—4 x 12 mm Screws (4)
N—10-32 x 1.75 Screw
O—1/4" Cable clamps (2)
P—Plastic spacer
Q—1/4" Rubber washer
R—Cable tie, 5.6" (4)
S—Cable tie, 20”
J
K
L
M
N
O
P
Q
R
I
S
G
(Cable not shown)
C
D
E
B1
F
(Fishfinder 90)
B2
(Fishfinder 90)
(Fishfinder 140)
A
H
(Fishfinder 90 shown)

Fishfinder 90/140 Owner’s Manual 5
INSTALLING YOUR FISHFINDER
Installing the Transducer
Assembling the Transducer
1. Insert the rubber washer (Q) and plastic spacer (P)
into the transducer (G) at the same time. DO NOT
lubricate the rubber washer.
2. Route the cable toward the back of the transducer.
Slide the transducer into the transducer mount (H).
3. Place a 5 mm flat washer (J) on the 10-32 x
1.75" screw (N), and insert the screw through the
transducer mount, spacer, and rubber washer.
4. Place the remaining 5 mm flat washer on the
exposed end. Install the 10-32 lock nut (L) tight. You
can tighten the transducer further after installation
on the boat.
Mounting the Transducer on a
Trolling Motor
1. Slide the large cable tie (S) through the slot on the
transducer mount (H) with the ridges of the band
facing up until equal lengths extend on both sides of
the mount. (NOTE: For cold water, or heavy timber
or debris areas, a metal 4-5" worm gear clamp is
recommended.)
2. Position the mount gasket (I) on the curved top of
the transducer mount.
3. Place the transducer assembly
against the motor body of the
trolling motor, with the front of
the transducer pointed away
from the trolling motor
propeller.
Back of the transducer
Cable tie slot

6 Fishfinder 90/140 Owner’s Manual
INSTALLING YOUR FISHFINDER
4. Wrap the two ends of the cable tie around the motor
body. Place the pointed end of the cable tie through
the fastener hole on the opposite end and pull it
through until it is snug but not tight. (The cable tie
clicks when you pull it.)
5. Position the transducer so that it is parallel with the
bottom when in use, and make sure the gasket is
aligned properly. Pull the cable tie end until tight.
Trim off the excess, if necessary. Tighten the 10-32
locking nut until it touches the mounting bracket and
then tighten 1/4 turn more. (Do not overtighten.)
6. Route the 30’ (9 m) transducer cable using the
supplied cable ties to secure the cable to the motor
shaft. You can fill the forward-facing portion (except
the cable tie pocket) of the transducer mount with
sealant to avoid accumulating debris.
Mounting the Transducer on a Transom
When selecting a transom mount location, consider the
following for optimal performance:
• For your sonar to operate properly, the transducer
must be located in calm water. DO NOT mount the
transducer behind strakes, rivet lines, struts, fittings,
water intake, discharge ports, eroding paint, or
anything that creates turbulence.
• Mount the transducer as close to the center of the
boat as possible.
• DO NOT cut the transducer lead. (This voids your
warranty.)
• DO NOT mount the transducer in locations where it
might be jarred when launching, hauling, trailering,
or storage.
• DO NOT mount the transducer in the path of the
prop on single-drive boats. The transducer can cause
cavitation that can degrade the boat’s performance
and damage the prop. On twin-drive boats, mount
the transducer between the drives, if possible.

Fishfinder 90/140 Owner’s Manual 7
INSTALLING YOUR FISHFINDER
Make sure the transducer is below
water level when the boat is on plane
at high speed.
Apply marine sealant to all screw threads to prevent water from
seeping into the transom.
Mount the transducer parallel with the
water line.
Do not mount the transducer behind
strakes, rivet lines, struts, fittings, water
intakes or discharge ports.
To mount the transducer on a transom:
Tool List (not included)—drill, 3/8" wrench or
socket, 5/32" and 1/8" drill bits, masking tape, #2
Phillips screwdriver, and marine sealant.
1. Position the transducer mount at the selected
transom location. Make sure the transducer
is parallel with the water line. Mark the center
locations of each hole on the transducer mount.
(See the figures on the next page.)
2. Using a 5/32" bit, drill the pilot holes approximately
1" (25 mm) deep at the marked locations. To avoid
drilling the holes too deep, wrap a piece of tape
around the bit at 1" from the point of the bit.
3. Apply marine sealant to the 5 x 30 mm screws.
Attach the transducer assembly to the transom
using the 5 x 30 mm screws. Adjust the transducer
assembly to extend beyond the bottom of the
transom approximately 1/8" (3 mm) on fiberglass
hulls or 3/8" (10 mm) on aluminum hulls. Adjust the
transducer assembly to be aligned parallel with the
water.

8 Fishfinder 90/140 Owner’s Manual
INSTALLING YOUR FISHFINDER
4. Tighten the 10-32 locking nut until it touches the
mounting bracket, and then tighten 1/4 turn more.
(Do not overtighten.)
5. Place the first cable clamp on the transducer cable
approximately one third of the distance between
the transducer and the top of the transom. Mark
the location. Using a 1/8" bit, drill a pilot hole
approximately 3/8" (10 mm) deep.
6. Attach the cable clamp using a 4 x 12 mm screw.
Coat the screw with marine sealant before
installation. Repeat steps 5 and 6 using the other
cable clamp.
7. Route the transducer cable, as needed, to the
Fishfinder. DO NOT CUT THE CABLE. Avoid
routing the cable with electrical wires or other
sources of electrical interference.
OK
Level
Drill pilot holes here.
Vertical
Bottom of the transom
Align with the
transom bottom. The
transducer should
extend 1/8" below
fiberglass hulls or
3/8" below aluminum
hulls.
Keep it parallel with the water line.

Fishfinder 90/140 Owner’s Manual 9
INSTALLING YOUR FISHFINDER
Installing the Fishfinder Unit
Selecting a Fishfinder Location
Select a Fishfinder installation location that allows you to
view and operate it easily while operating the vessel. Select
a mounting surface strong enough to support the weight
of the Fishfinder and protect it from excessive vibration or
shock. DO NOT mount the bracket in a location where the
Fishfinder is exposed to extreme temperature conditions.
When installing the mounting bracket, be sure to allow
room to connect and rout the power cable.
Mounting the Bracket Assembly
Tool List (not included)—drill, screwdriver (Phillips or
standard), three #8 pan-head machine bolts with matching
nuts and washers, and a 5/32" drill bit; or three #8 pan-
head, self-tapping screws and a 1/16" drill bit.
To mount the bracket assembly:
1. Using the tilt mount bracket (Fishfinder 90) or the
swivel base (Fishfinder 140; Fishfinder 90 option)
as a template, mark the location of the three holes
that you use to secure the bracket to the mounting
surface.
2. If securing the base with machine bolts, drill three
5/32" holes at the locations you marked; or, if
securing the base using self-tapping screws, drill
1/16" starter holes at the locations you marked. Drill
starter holes no deeper than half the screw length.
3. Secure the tilt mount bracket or swivel base with
three bolts or screws. DO NOT OVERTIGHTEN.
4. If you are using the swivel mount, place the swivel
mount bracket over the swivel base and secure it
with the short knob.
(Fishfinder 90) (Fishfinder 140;
Fishfinder 90 option)
Swivel base
Swivel mount bracket
Tilt mount bracket

10 Fishfinder 90/140 Owner’s Manual
INSTALLING YOUR FISHFINDER
Installing the Unit on the Mount Bracket
To install the Fishfinder on the mount bracket:
1. Align the slot on the back of the Fishfinder with the
long mounting knob, and slide the Fishfinder into
place. If necessary, adjust the long knob to spread
the bracket arms apart. (Turn counter-clockwise to
widen the bracket arms and clockwise to tighten.)
2. Adjust the Fishfinder angle, and tighten the long
mounting knob until snug.
3. For the Fishfinder 140 (Fishfinder 90 option), rotate
the swivel mount bracket by twisting it left or right.
The bracket clicks as you turn it. Select a good
viewing angle, and then tighten all knobs.
Installing the Wiring Harness
The Fishfinder comes with a wiring harness that connects
the Fishfinder to power and the transducer with one easy-
to-remove connection. If it is necessary to extend the power
wires, use 22 AWG wire. DO NOT cut the transducer
cable, because this voids your warranty. If your boat has an
electrical system, you might be able to wire the Fishfinder
directly to an unused holder on your current fuse block. If
you are using the boat’s fuse block, remove the in-line fuse
holder supplied with the Fishfinder. You can also wire the
Fishfinder directly to the battery.
CAUTION: The Fishfinder input voltage is 10–18
volts DC. Do not exceed this voltage, because this can
damage the Fishfinder and void the warranty.
To install the wiring harness:
1. Determine the polarity of the power source using a
test light or volt meter.
2. Install the red (+) wire on the positive fuse holder or
battery terminal.

Fishfinder 90/140 Owner’s Manual 11
INSTALLING YOUR FISHFINDER
3. Install the black (-) wire on the negative fuse holder
or battery terminal.
4. Install a 2 Amp fuse in the fuse holder (fuse block
only).
5. Align the notches on the cable plug and on the back
of the Fishfinder. Insert the cable into the connector
and turn the lock ring counter-clockwise until it
stops.
Testing the Transom Mount
Installation
Perform this test after you install the Fishfinder. Because
you need water to carry the sonar signal, the Fishfinder
does not function properly with the transducer out of the
water. When you place your boat in the water, CHECK
FOR LEAKS around the screw holes that are below the
water line. DO NOT leave your boat in the water for an
extended period of time without checking for leaks.
To test the transom mount installation:
1. Begin testing the installation at a slow speed. If the
sonar appears to be working properly gradually
increase the boat’s speed observing the sonar’s
operation. If the sonar signal suddenly is lost or the
bottom return is severely degraded, note the speed
at which this occurs.
2. Return the boat to the speed at which the signal
was lost. Make moderate turns in both directions,
and see if the signal improves.
3. If the signal strength improves while turning, adjust
the transducer so that it extends another 1/8"
below the transom of the boat. It might take several
adjustments to eliminate the degradation.
4. If the signal does not improve, it might be necessary
to move the transducer to a different location.

12 Fishfinder 90/140 Owner’s Manual
OPERATING YOUR FISHFINDER
OPERATING YOUR FISHFINDER
ENTER
MENU
Power key—turns the Fishfinder on or
off and controls the screen backlight.
(Fishfinder 140 is shown.)
ENTER key—confirms a selection.
MENU key—shows or exits a menu.
Arrow keys—the up and down Arrow
keys select an item on a menu. Only
the Fishfinder 140 has the right and left
Arrow key that cycles through the Main
menu options.
Understanding Basic Functions
To turn on the Fishfinder:
Press and release the Power key.
To turn off the Fishfinder:
Press and hold the Power key.
To change the backlight level:
Press the Power key repeatedly to cycle between off, low,
and high.
To view or change settings for your Fishfinder, you can use
two menus: the Main menu and the Setup menu.
To change a setting:
1. Press MENU. The Main menu appears.
2. Use the Arrow keys to move the selection arrow to
an option, and press ENTER. The settings appear.
If you select Setup, the Setup menu appears. See
“Using the Setup Menu” on page 14.

Fishfinder 90/140 Owner’s Manual 13
OPERATING YOUR FISHFINDER
3. To select a setting, use the Arrow keys to move
the selection arrow, and press ENTER. (When you
reach the end of a menu, the selection arrow wraps
to the beginning.) Press and hold an Arrow key to
rapidly advance the selection speed.
4. To close a setting or a menu, press MENU.
Using the Main Menu
From the Main menu, you can change the Range, Gain,
Scroll, Zoom, and View settings.
• To view the current menu settings, press MENU.
• To exit any window, press MENU.
• To quickly change a setting for the current option
that appears in the upper-left corner of the screen
(for example, the Range option in the above screen),
press an Arrow key.
Options and Settings
The following settings reset to the system defaults each
time you turn on the Fishfinder.
Range—sets the maximum depth that you want the
Fishfinder to display. Auto (default) automatically tracks
the bottom, or you can set the range, 5–600 feet.
Gain—controls the sensitivity of the Fishfinder’s sonar
receiver. Auto (default) automatically sets the sonar
sensitivity, or you can set the gain. To see more detail on
the screen, increase the receiver sensitivity by selecting a
higher gain. If there is too much detail or if the screen is
cluttered, lower the sensitivity (lower the gain) to increase
the clarity of the screen.

14 Fishfinder 90/140 Owner’s Manual
OPERATING YOUR FISHFINDER
Scroll—sets the rate that the graph scrolls from right to
left. If you are sitting still or the graph is moving too fast,
slowing or pausing the graph can help. The settings are
Ultra, Fast (default), Medium, Slow, and Paused.
Zoom—sets the zoom level for the screen. Off is the
default.
View—when you select a 2X or 4X Zoom setting, you
can select a specific area to view on the screen. You can
also allow the Fishfinder to automatically select a zoomed
viewing area based on the bottom.
Using the Setup Menu
To access the Setup menu:
1. Press MENU. The Main menu appears.
2. Use the Arrow keys to move the selection arrow to
Setup, and press ENTER. The options appear.
Options and Settings
Your changes to the following settings are used until you
set the System Defaults option to Yes.
Alarms
Battery—controls an alarm that sounds when the battery
is reaching a critical state of discharge. The settings are
Off (default) and 8.5–16.0 volts remaining.
Shallow—sets an alarm for the shallow water warning at a
specific depth. The settings are Off (default) and 1.0–600
feet.
Deep—sets an alarm for the deep water warning at a
specific depth. The settings are Off (default) and 1.0–600
feet.
Fish—turns on or off (default) an alarm that sounds when
the Fishfinder detects what it determines to be a fish.