Section 5 - Maintenance
Page 78
90-8M0070851
eng
AUGUST 2012
Sterndrive Corrosion Protection Components
To help control the effects of galvanic corrosion, Mercury Diesel sterndrives come with several sacrificial anodes and other
corrosion protection devices. For a more comprehensive explanation of corrosion and corrosion protection, refer to the
Marine
Corrosion Protection Guide
(90‑88181301).
1 -
Gearcase anodic plate
2 -
Anode plate
3 -
MerCathode system
4 -
Anode kit
5 -
Trim cylinder anodes
6 -
Bearing carrier anodes
7 -
Propeller shaft anode (Bravo III standard)
NOTICE
Washing the MerCathode assembly can damage components and lead to rapid corrosion. Do not use any cleaning
equipment such as brushes or high‑pressure washers to clean the MerCathode assembly.
Do not pressure wash the MerCathode assembly. Doing so will damage the coating on the reference electrode wire and
decrease the corrosion protection.
MerCathode—mounted to the underside
of the gimbal housing
a -
MerCathode reference electrode
b -
Do not paint
c -
Do not pressure wash
Anodes and MerCathode System Locations
IMPORTANT: Replace sacrificial anodes if eroded 50 percent or more.
The following sacrificial anodes are installed at different locations on your power package. These anodes help protect against
galvanic corrosion by sacrificing their metal to be slowly eroded instead of the metal components on the power package.
MerCathode system—
The electrode assembly replaces the anode block. The system should be tested to ensure adequate
output. The test should be performed where the boat is moored, using a Quicksilver Reference Electrode and Test Meter.
Contact your Mercury Diesel authorized repair facility.
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