24 Series 4180 Powerhead
: Remove the gasket (1) and pump
diaphragm (2).
If the gasket and diaphragm are
stuck together, separate them
carefully.
: Check the diaphragm and gasket
and replace if necessary.
The diaphragm is the most delicate
part of the carburetor. The
diaphragm material is subjected to
continuous alternating stresses and
eventually shows signs of fatigue,
i.e. the diaphragm distorts and
swells and has to be replaced.
: Remove flange body (1) with idle
speed screw.
: Remove the gasket (1) and pump
diaphragm (2).
Reassemble in the reverse
sequence.
: The pump diaphragm (1) and
gasket (2) are held in position by
the cast pegs on the flange body
with idle speed screw (3).
: Gasket (1) and pump diaphragm
(2) are held in place by the cast
pegs on the end cover (5).
: Install the spring (4) and spring
retainer (3) in the housing base
(5). Fit the diaphragm (2) and
gasket (1) and screw the
assembly to the carburetor.
The spring retainer’s integrally cast
guide points toward the spring (4).
– Fit the screws and tighten them
down firmly.