Humminbird PiranhaMAX 155 Installation And Operation Manual page 25

NOTE: It is often necessary to make several incremental transducer
adjustments before optimum high speed performance is achieved. Due to the
wide variety of boat hulls, however, it is not always possible to obtain high
speed depth readings.
6. Once you have reached a consistently good sonar signal at the desired
speeds, you are ready to lock down the transducer settings. Remove the
transducer from the bracket (after noting where the ratchets are
assembled), then re-align the mounting bracket against the transom of the
boat to match the traced silhouette. Check the bracket position with the
level again to make sure it is still level, then mark the third mounting hole
using a pencil or marker. Unscrew and remove the mounting screws and
the transducer bracket and set aside.
7. Drill the third mounting hole, using a 5/32" drill bit. Use a marine-grade
silicone sealant to fill all three drilled mounting holes, especially if the
holes penetrated the transom wall.
NOTE: On fiberglass hulls, it is best to use progressively larger drill bits to
reduce the chance of chipping or flaking the outer coating.
Fully Tighten All Three
Mounting Screws
Figure 26
8. Re-position the transducer bracket against
the transom of the boat, then hand-install all
three screws. Make sure that the transducer
location has not changed, then fully tighten
all three mounting screws (Figure 26). Hand
tighten only!
9. Re-install the transducer to the mounting
bracket, making sure to assemble the ratchets
in the same location they had before. (See
Figures 17a - 17d and Figure 20 - 21).
If you have performed the preceding
procedures correctly, the transducer should
be level and at the right height for optimal
operation.
17
Transom Transducer Installation