821306T28 Mercury GEAR HOUSING ASSEMBLY

Use the following procedure to prime the fuel system:If air enters the fuel system, the air must be purged from the fuel system before the engine can be started. Air can enter the fuel system when the following events occur:
The fuel tank is empty or the fuel tank has been partially drained.
The low-pressure fuel lines are disconnected.
A leak exists in the low-pressure fuel system.
The fuel filter is replaced.Mechanical Priming Pump
Primary Filter
Ensure that the air is removed from the primary filter before you prime the secondary fuel filter. Refer to illustration 1.
Illustration 1 g01316878
This filter may not be installed on the engine.
(1) Vent screwsPriming the Primary Fuel Filter
Illustration 2 g06221845
If equipped, operate the hand priming pump (2) until fuel free from air comes from the vent screw (1). Then close vent screw (1) by hand.
Illustration 3 g06221885
If the hand priming pump is not installed, operate the starting motor to crank the engine. Crank the engine to operate the transfer pump (3). Do not operate the transfer pump for more than 15 seconds. After 15 seconds, stop and wait 30 seconds before operating the starting motor.
When fuel free from air comes from the vent screw (1) close vent screw (1) by hand.Secondary Fuel filters
There are three types of fuel filter that may be installed on the engine.
Element
Canister
Spin-on filter with fuel priming pump
Illustration 4 g01327360
Element
(2) Fuel valve
(3) Vent screw
Illustration 5 g01327361
Canister
(4) Vent screw
Illustration 6 g01327363
Spin-on filter with fuel priming pump
(5) Vent screwVent screw (3) is installed on the filter that has an element. Vent screw (4) is installed on the fuel filter that has a canister. Vent screw (5) is installed on the spin-on filter.Priming the system
Note: Some fuel system will use gravity to prime the primary fuel filter. When gravity is used to deliver the fuel, ensure that the fuel tank is full and that all stop valves in the fuel line are open.There are four different types of systems that can be installed on the engine to prime the fuel system. Refer to illustration 7.
Hand priming pump
In-line hand priming pump
Electrical priming pump
Transfer pump that is operated by the starting motor
Illustration 7 g06523817
(6) Hand priming pump
(7) In-line priming pump
(8) Electrical priming pump
(9) Fuel transfer pump with hand priming
Illustration 8 g06523835
(10) Connector bolt
(11) Fuel return line
(12) Connector boltHand Priming Pump 6
To identify the hand priming pump, refer to illustration 7.
Ensure that fuel valve (2) for the fuel filter that has an element is in the ON position. Refer to illustration 4.
Loosen vent screw (3, 4 or 5) on the fuel filter.
Operate hand priming pump (6). When fuel free from air flows from the vent screw tighten the vent screw.
Loosen connection (10 or 12) at the fuel injection pump. Refer to illustration 8.Note: Fuel return line (11) may need to be removed to prime the fuel system.
Operate the hand priming pump. When fuel free from air flows from the connections tighten the connecting bolt.
The engine should now be able to start. Operate the starting motor to start the engine.Note: Do not operate the starting motor for more than 15 seconds. If the engine does not start after 15 seconds, stop and wait for 30 seconds before trying again.In-line Priming Pump 7
To identify the in-line priming pump, refer to illustration 7.
Ensure that fuel valve (2) for the fuel filter that has an element is in the ON position. Refer to illustration 4.
Loosen vent screw (3, 4 or 5) on the fuel filter.
Operate in-line priming pump (7). When fuel free from air flows from the vent screw tighten the vent screw.
Loosen connection (10 or 12) at the fuel injection pump. Refer to illustration 8.Note: Fuel return line (11) may need to be removed to prime the fuel system.
Operate the in-line priming pump. When fuel free from air flows from the connections tighten the connecting bolt.
The engine should now be able to start. Operate the starting motor to start the eng