Mercury 300R HD CMS Mechanical, Operation And Maintenance Manual, Page: 67 / 99

Fuel System
!
WARNING
Fuel is flammable and explosive. Ensure that the key switch is off and the
lanyard is positioned so that the engine cannot start. Do not smoke or allow
sources of spark or open flame in the area while servicing. Keep the work
area well ventilated and avoid prolonged exposure to vapors. Always check
for leaks before attempting to start the engine, and wipe up any spilled fuel
immediately.
IMPORTANT: Use an approved container to collect and store fuel. Wipe up
spilled fuel immediately. Material used to contain spilled fuel must be disposed
of in an approved receptacle.
Before servicing any part of the fuel system:
1. Stop engine and disconnect the battery.
2. Perform fuel system service in a well‑ventilated area.
3. Inspect any completed service work for sign of fuel leakage.
FUEL LINE INSPECTION
Visually inspect the fuel line for cracks, swelling, leaks, hardness, or other signs
of deterioration or damage. If any of these conditions are found, the fuel line
must be replaced.
LOW-PRESSURE FUEL FILTER
The low‑pressure fuel filter can be serviced as a general maintenance item
when the water‑in‑fuel alarm is activated.
!
WARNING
Fuel is flammable and explosive. Ensure that the key switch is off and the
lanyard is positioned so that the engine cannot start. Do not smoke or allow
sources of spark or open flame in the area while servicing. Keep the work
area well ventilated and avoid prolonged exposure to vapors. Always check
for leaks before attempting to start the engine, and wipe up any spilled fuel
immediately.
Removal
IMPORTANT: Use an approved container to collect and store fuel. Wipe up
spilled fuel immediately. Material used to contain spilled fuel must be disposed
of in an approved container.
1. Verify the ignition key switch is in the OFF position and that the lanyard
switch is positioned so the engine cannot start.
2. Remove the top cowl.
3. Locate the fuel filter on the starboard aft side of the engine near the
bottom spark plug.
MAINTENANCE
eng
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