Engine Seawater Pump Inspection; Corrosion Protection; General Information; Engine Corrosion Protection Components - Mercury MerCruiser Series Manual

2. Utilize Mercury Marine's 8M0117941 kit to connect a flushing hose from a water tap to the seawater inlet hose connected
to the seawater pump inlet.
3. Partially open the water source to about 1/2 maximum. Do not use full water pressure.
4. Place the remote control in the neutral, idle speed position and start the engine.
Operating the engine at high speeds creates suction, which can collapse the water supply hose and overheat the engine. Do
not operate the engine above 1400 RPM without a sufficient cooling water supply.
5. Operate the engine at idle speed in neutral for about 10 minutes, or until the discharge water is clear.
6. Observe the water temperature gauge to ensure that the engine is operating in the normal range.
7. Stop the engine.
8. Shut off the water tap.
9. Remove the adapter from the seawater pump inlet hose connection.
10. To prevent water from siphoning into the boat or engine, do not open the seacock or connect the water inlet hose at this
time.
11. Place an appropriate tag on the key switch stating that the seacock must be opened or the seawater inlet hose must be
reconnected before operating the engine.

Engine Seawater Pump Inspection

IMPORTANT: Mercury strongly recommends that this service be performed by a Mercury Diesel authorized repair facility.
Remove and inspect the engine seawater pump at the interval specified in the Maintenance Schedule. See your Mercury
Diesel authorized repair facility.

Corrosion Protection

General Information

Whenever two or more dissimilar metals (such as those found on this power package) are submerged in a conductive solution
such as saltwater, polluted water, or water with a high mineral content, a chemical reaction takes place causing electrical
current to flow between metals. The electrical current flow causes the metal that is most chemically active, or anodic, to erode.
This erosion is known as
package components exposed to water.
To help control the effects of galvanic corrosion, Mercury power packages 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.
IMPORTANT: Replace sacrificial anodes if eroded 50% or more. Mercury strongly recommends avoiding the use of anodes
from other manufacturers. Refer to your Mercury Diesel authorized repair facility for additional information.

Engine Corrosion Protection Components

The engine is equipped with two sacrificial anodes that are immersed within the seawater path. The anode retards the
corrosion process, protecting the engine and the seawater cooling system from corrosion.

Anode Removal

1. Turn the engine off and allow the engine to cool.
90-8M0117076 FEBRUARY 2018
eng
a
b
galvanic corrosion and, if it is not controlled, it will eventually cause the need for replacement of power
a - Seawater pump
b - Seawater inlet hose
64999
NOTICE
Section 5 - Maintenance
Page 67