Mercury MerCruiser 5.7 Horizon, User Manual

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Section 5 - Maintenance
90-899883173 DECEMBER 2007 Page 81
c. Using a suitable adapter, connect the flushing hose from the water source to the
water inlet of the seawater pump.
d. Proceed to step 3.
NOTICE
Flushing the engine when it is not operating will result in water collecting in the exhaust
system, damaging the engine. Do not supply flush water for more than 15 seconds without
the engine operating.
3. Completely open the water source to provide maximum water supply.
4. Place the remote control in the neutral idle speed position.
5. Immediately start the engine.
NOTICE
Operating the engine out of the water at high speeds creates suction, which can collapse
the water supply hose and overheat the engine. Do not operate the engine above 1400
RPM out of the water and without sufficient cooling water supply.
6. Depress the throttle only button and slowly advance the throttle until the engine reaches
1300 RPM (± 100 RPM).
7. Observe the water temperature gauge to ensure that the engine is operating in the
normal range.
8. Operate the engine with the transmission in neutral for a minimum of 10 minutes.
9.
For power packages operated in salty, brackish, mineral‑laden or polluted water:
Continue to operate the engine until the discharge water is clear.
10. Slowly return the throttle to idle speed position.
NOTICE
Flushing the engine when it is not operating will result in water collecting in the exhaust
system, damaging the engine. Do not supply flush water for more than 15 seconds without
the engine operating.
11. Stop the engine.
12. Immediately shut off the supply water and remove the flushing attachment.
13. Install the water inlet hose to the seawater inlet of the seawater pump or V‑Drive water
inlet.
14. Tighten hose clamp securely.
15. Attach to the next engine, if equipped, and repeat procedure.
The Boat In the Water
IMPORTANT: Flushing the power package is most effective when performed with the boat
out of the water.