Mercury 305 CID, Service Manual, Page: 43 / 967

1B-26 - MAINTENANCE 90-823225--1 1096
! CAUTION
If boat is in the water, seacock (water inlet valve),
if so equipped, must be left closed until engine is
to be re-started, to prevent water from flowing
back into cooling system and/or boat. If boat is
not fitted with a seacock, water inlet hose must
be left disconnected and plugged (to prevent wa-
ter from flowing back into cooling system and/or
boat). As a precautionary measure, attach a tag
to the ignition switch or steering wheel of the
boat with the warning: Open seacock or recon-
nect water inlet hose before starting engine.
IMPORTANT: Observe the following information
to ensure complete draining of cooling system.
•
Engine must be as level as possible.
•
A wire should be repeatedly inserted into all
drain holes to ensure there are no obstruc-
tions in passages. Remove petcock, if neces-
sary, to insert wire completely into drain hole.
IMPORTANT: To prevent threads in manifolds, el-
bows and cylinder blocks from rusting out dur-
ing storage, reinstall plugs using Quicksilver
Perfect Seal on threads. Never leave drain plugs
out during storage.
NOTE: If possible, place a container under drains
and hoses to prevent water from draining into boat.
! CAUTION
If engine is equipped with Closed Cooling Sys-
tem, Closed Cooling section must be kept filled
with a solution of ethylene glycol antifreeze and
water (mix antifreeze to manufacturer’s recom-
mended proportions to protect engine to lowest
temperature to which it will be exposed). DO NOT
USE PROPYLENE GLYCOL antifreeze in closed
cooling section. Seawater section, however,
must be drained completely.
! CAUTION
A discharged battery can be damaged by freez-
ing.
Layup
NOTICE
Refer to “Cold Weather or Extended Storage,”
“Precautions,” in this section, BEFORE pro-
ceeding.
1. Fill fuel tank(s) with fresh gasoline that does not
contain alcohol and a sufficient amount of Quick-
silver Gasoline Stabilizer and Conditioner to treat
the gasoline.
IMPORTANT: If boat is to be placed in storage
(with fuel containing alcohol in fuel tanks), car-
buretors must be run dry at idle RPM. Fuel tanks
should be drained completely and Quicksilver
Gasoline Stabilizer and Conditioner added to any
fuel remaining in the tank. Also, refer to “Fuel
Specifications,” see Table of Contents.
2. Replace all fuel filters
3. Start engine and check for fuel leaks.
4. Run engine sufficiently to heat it to normal operat-
ing temperature; shut off engine and change oil
and filter.
5. If boat has been operated in salty, polluted or min-
eral-laden waters, flush cooling system.
a. For engines with carburetors:
(1) Remove flame arrestor assembly and re-
start engine. While operating engine at
fast idle (1000-1500 RPM), fog internal
surfaces of induction system and com-
bustion chambers by squirting approxi-
mately 8 ounces (227 grams) of Quicksil-
ver Storage Seal or SAE 20W engine oil
into carburetor bores. Stall engine by
squirting last 2 ounces (57 grams) of Stor-
age Seal or oil rapidly into carburetor.
Turn ignition to OFF.
b. For fuel injected engines with VST:
! WARNING
Fuel injection system is pressurized. A special
procedure must be used to remove this pressure
before removing the plug from vapor separator
tank. DO NOT attempt to remove plug without
having pressure removed. Fuel could spray on
hot engine causing fire or explosion.
(1) Relieve fuel pressure from system. Refer
to “Fuel Pressure Relief Procedure” in
Section 5C.