MerCruiser 350 Magnum MPI, Operation & Maintenance Manual

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CC57
Flushing Cooling System
! WARNING
When flushing, be certain the area around propeller is clear, and no one is standing nearby. To avoid possi-
ble injury, remove propeller.
! CAUTION
Do not run engine above 1500 RPM when flushing. Suction created by seawater pickup pump may collapse
flushing hose, causing engine to overheat.
! CAUTION
Watch temperature gauge on dash to ensure that engine does not overheat.
! CAUTION
If cooling system is to be flushed with boat in the water, water inlet valve (if so equipped) must be closed,
or water inlet hose must be disconnected and plugged to prevent water from flowing into boat.
! CAUTION
If boat is in the water, do not open water inlet valve until engine is to be restarted, to prevent contaminated
water from flowing back into engine.
To prevent silt and/or salt buildup in cooling system, flush with freshwater at specified intervals.
1
Disconnect water inlet hose (Lower hose) from aft end of seawater pickup pump.
2
Using appropriate connector, connect hose between connector and water tap. Partially open water tap (about
1/2 maximum). Place remote control in NEUTRAL, idle speed position and start engine. Operate engine at idle
speed, in NEUTRAL, for about 10 minutes, or until discharge water is clear. Stop engine. Shut off water, remove
flushing connector from pump inlet and reconnect water inlet hose. Tighten hose clamp securely.
CC58
Seawater Pump Impeller
This maintenance should be performed by an Authorized MerCruiser Dealer.
3
Seawater pump impeller should be inspected whenever insufficient seawater flow is suspected (if operating
temperature exceeds normal range).