MerCruiser 350 MAG Owner's Manual page 110

Section 5 - Maintenance
20. Insert the dust cover in the flush socket on the engine.
IMPORTANT: If the unit is to be stored in the water, the seacock should remain closed until
time of usage. If unit is to be stored out of the water, open the seacock.
21. Open the seacock, if equipped, or reconnect the alternative water inlet source prior to
operating the engine.
Page 102
Dust cover installed in the flush socket
a - Dust cover
a
b
18490
b - Flush socket
90-864195072 OCTOBER 2007