Stihl TS 420 Manual page 83

: Carefully remove the end
cover (1).
: Carefully remove the gasket and
pump diaphragm from the end
cover.
1
2
: Carefully separate the pump
diaphragm (1) and gasket (2).
The diaphragm material is
subjected to continuous alternating
stresses and eventually shows
signs of fatigue. In other words, the
diaphragm distorts and swells and
must be replaced.
82
– Examine the pump diaphragm for
signs of damage and wear, fit a
new gasket.
– Examine the fuel strainer for
signs of fouling and damage.
1
Clean or replace it if necessary,
b 14.
1
: Pull the fuel strainer (1) out of the
carburetor housing with a needle.
– Reassemble parts in reverse
order.
2
2
: Fit the gasket (1) so that it
matches the contour of the end
cover (arrows) and is secured in
the pegs (2).
2
: Fit the diaphragm (1) so that it
matches the contour of the
gasket (arrows) and is secured in
the pegs (2).
1
– Align the end cover (1) so that the
idle speed screw (arrow) points
towards the adjusting screws.
1
: Position the end cover (1) on the
carburetor housing from below so
that the gasket and pump
diaphragm remain secured to the
end cover.
Turn the throttle shaft slightly in
open direction so that the end cover
can be fitted without resistance.
– Move the end cover (1) back and
forth slightly until the pegs on the
end cover engage in the holes in
the carburetor housing.
1
2
TS 410, TS 420