Makita EH561 Service Manual page 20

(1) Throttle Valve
(2) Tamper Resistant Plug:
(3) Low-Speed Needle:
(4) Inlet Screen:
(5) Needle Valve:
(6) Fuel Inlet:
(7) Metering Lever Spring:
(8)
Metering Lever:
(9) Metering Diaphragm:
(10) Metering Chamber:
(1 1) Fuel Pump Diaphragm:
(12) Fuel Outlet:
(13) Engine Pulse:
(14) Main Jet:
(15) Nozzle:
(16) Idle Adjust Screw:
(1 7) Primer Pump:
(18)
Combination Valve:
(19) Main Check Valve:
(20) Outlet Valve:
(21) Inlet Valve:
Controls engine output.
Prevents entry of air and foreign matter.
Regulates fuel at idling or slow rpm.
Filters fuel intake to carburetor.
Controls fuel supply to metering chamber from fuel pump.
For fuel intake.
Works together with metering diaphragm to ensure constant pressure
in metering chamber.
Conveys operation of metering diaphragm to needle valve.
Works up or down depending on difference of pressure inside engine
and atmospheric pressure so as to open or close the needle valve
through the metering lever and metering spring.
Supplies fuel via nozzle by fuel tank.
Undulates, in keeping with engine pulse. This action serves to send fuel
to the diaphragm chamber.
Allows excess fuel to return to the tank during primer pump operation.
Takes the negative or positive pressure building up in the crankcase
under piston operation and makes the fuel pump diaphragm work
accordingly.
Regulates fuel at high speed.
Outlet for fuel sent into the cylinder.
Controls idling rpm.
Brings fuel up from the fuel tank into the metering chamber.
Acts as a check valve between primer pump intake and charge.
Prevents air in the nozzle from entering the metering chamber when
the primer pump is being worked.
Works just the opposite of the inlet valve.
Valve opens when diaphragm is subjected to negative pressure, and
closes under positive pressure, corresponding to the pump action.
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