Flushing The Cooling System; Fuel System - Mercury 40 Service Manual

Flushing The Cooling
System
Flush the internal water passages of the outboard
with fresh water after each use in salt, polluted, or
muddy water. This will help prevent a buildup of de-
posits from clogging the internal water passages.
Use a Quicksilver accessory (or equivalent) flushing
attachment.
WARNING
To avoid possible injury when flushing, remove
the propeller. Refer to Propeller Replacement.
1. Remove propeller (refer to Propeller Replace-
ment). Install the flushing attachment so the rub-
ber cups fit tightly over the cooling water intake
holes.
2. Attach a water hose to the flushing attachment.
Turn on the water and adjust the flow so water is
leaking around the rubber cups to ensure the en-
gine receives an adequate supply of cooling wa-
ter.
90-852572R1 JANUARY 1998
3. Start the engine and run it at idle speed in neutral
shift position.
4. Adjust water flow (if necessary) so excess water
continues leaking out from around the rubber
cups to ensure the engine is receiving an ade-
quate supply of cooling water.
5. Check for a steady stream of water flowing out of
the water pump indicator hole. Continue flushing
the outboard for 3 to 5 minutes, carefully monitor-
ing water supply at all times.
6. Stop the engine, turn off the water, and remove
the flushing attachment. Reinstall the propeller.

Fuel System

IMPORTANT: Gasoline containing alcohol (etha-
nol or methanol) can cause a formation of acid
during storage and can damage the fuel system.
If the gasoline being used contains alcohol, it is
advisable to drain as much of the remaining gas-
oline as possible from the fuel tank, remote fuel
line, and engine fuel system.
Fill the fuel system (tank, hoses, fuel pump, and car-
buretors) with treated (stabilized) fuel to help prevent
formation of varnish and gum. Proceed with following
instructions.
1. Portable Fuel Tank – Pour the required amount of
Quicksilver Gasoline Stabilizer (follow instruc-
tions on container) into fuel tank. Tip fuel tank
back and forth to mix stabilizer with the fuel.
2. Permanently Installed Fuel Tank – Pour the re-
quired amount of Quicksilver Gasoline Stabilizer
(follow instructions on container) into a separate
container and mix with approximately one quart
(one liter) of gasoline. Pour this mixture into fuel
tank.
IMPORTANT INFORMATION - 1B-3