I’m considering buying a boat equipped with a MerCruiser stern
drive and a MerCathode system already installed. How does this work?
H.B., via e-mail
The MerCathode system is designed to protect the immersed metal on your
boat against galvanic corrosion. As illustrated in the diagram, it consists
of a solid-state controller mounted internally and two small electrodes
installed on the outside of your boat’s transom below the waterline.
When the system is activated, the corrosion-sensor electrode (B) senses
the presence of galvanic current and then automatically directs the controller
(A) to maintain a sufficient current to the other electrode (C) to prohibit
the transfer of electrons that normally creates galvanic corrosion. The
system automatically adjusts for salinity and water temperature as well
as for the presence of exposed metal due to abrasion or other factors.
The system is powered by your boat’s 12-volt battery, but current
draw is very small, so under normal circumstances the chances of the system
causing unnecessary drain on your battery should not be a concern. The
only drawback is that if power is interrupted due to a dead battery or
interruption of the shore-power connection, protection ceases.
For further information, contact Mercury Marine at www.mercurymarine.com.
The starter on our boat’s PWC has been turning over slowly. What
should we check? P.H., via e-mail
First check your battery with a hydrometer. If the reading is below 1.230,
recharge it. If the battery does not take a full charge, you’ll need
to replace it. If your battery is okay, inspect your wiring harness for
poor contact at the starter solenoid and starter motor, as it may have
shaken loose during operation. Also look for corrosion on the terminals
and brighten them if necessary.
If you continue to have problems, the causes of which can range from a
faulty starter switch to a burned-out starter motor, it’s probably
best to call in a mechanic.
In addition, because PWCs are prone to jet-pump restrictions, such a blockage
may mask what appears to be a starter problem. Check for weeds, rocks,
or other debris that may be locking or binding up the impeller.
So far I’ve been unsuccessful in bending a flexible copper line without
kinking it. I don’t want to buy a tubing bender, as I’ll probably
have no use for it in the future. Any suggestions? S.S., via e-mail
Block one end of the tube with tape and fill it with dry sand before bending
it. The sand will prevent the walls from kinking. Wash the sand out completely
and allow the tube to dry before installing it.
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