Tecumseh AH520 -, Руководство пользователя

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13
OUTBOARD CARBURETORS
Carburetors on outboard applications use float type
which have a separate idle speed fuel pickup tube
pressed into the casting. The idle mixture screw is
located on the top of the carburetor near the engine.
This carburetor has been manufactured with 2 different
types of inlet needle and seats. One has a hard needle
with a synthetic rubber seat, the other has a non-
replaceable brass seat with a synthetic rubber tipped
needle.
IDLE SPEED
FUEL PICKUP
Outboard carburetors have a built-in fuel pump consisting
of a fuel pump element which inflates and deflates
with crankcase pulses which opens and closes two
flap valves in the fuel pump, thereby pumping fuel
from a remote tank to the carburetor float bowl.
When replacing the fuel pump element, install with
the slot opening at a 45
o
angle as illustrated.
FUEL PUMP
ELEMENT
TAMPER RESISTANT CAP
(Pierce to Remove)
HIGH SPEED AIR BLEED
FIXED MAIN JET
FIXED IDLE
RESTRICTER JET
EMISSIONIZED DIAPHRAGM CARBURETION
BLUE THREAD
LOCK SEALANT
APPLIED
Loosen screw until it just clears
throttle lever, then turn screw in 1
turn.
Place detent reference mark to
proper location. See chapter
appropriate to specific carburetor.
THROTTLE SHAFT LEVER AND
RETURN SPRING
THROTTLE SHUTTER
IDLE SPEED ADJUSTMENT SCREW
Remove welch plug and blow air
through air passages.
IDLE,
INTERMEDIATE
AND AIR BLEED
ORIFICES
Check shaft for binding. Position
shutter opening towards inlet fitting
side of air horn.
Primer bulb models have a Teflon
one way valve, in or behind the fitting.
Remove and replace.
Proper installation of assembly is
important. See appropriate chapter
for procedures.
Gasket and diaphragm sequence
may be reversed on some models.
Head of rivet must touch inlet needle.
Hole must be clean. On models with
primer bulb, vent hole is very small
and is located off center or in the
primer bulb.
CHOKE SHAFT AND LEVER
CHOKE SHUTTER
*DIAPHRAGM
GASKET
*DIAPHRAGM
ATMOSPHERIC VENT HOLE
*INLET
FITTING
*INLET SEAT
GASKET
*INLET
NEEDLE
SEAT AND
SPRING
ASSEMBLY
MAIN NOZZLE
WITH CHECK BALL