Garmin 90/140 - Manual (Page 19)

Fishfinder 90/140 Owner’s Manual 13
I
NSTALLING
Y
OUR
F
ISHFINDER
> T
ESTING THE
T
RANSOM
M
OUNT
I
NSTALLATION
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.