STIHL 020 T
48
10.2.3 Servicing
10.2.2 Leakage Testing
• Disconnect the choke rod from
the choke shaft.
The carburetor can be tested for
leaks with the carburetor and
crankcase tester (1).
• Remove the carburetor - see 10.2.1.
• Use fuel line (2) with nipple (3) as
adapter to make connection bet-
ween tester and carburetor's elbow
connector.
• Push the nipple into the tester's
pres-sure hose.
• Close the vent screw (4) on the
rubber bulb and pump air into
the carburetor until the pressure
gauge shows a reading of approx.
0.4 bar (5.8 psi).
If this pressure remains constant,
the carburetor is airtight. However,
if it drops, there are two possible
causes:
1. The inlet needle is not sealing
(foreign matter in valve seat or
sealing cone of inlet needle is
damaged or inlet control lever
sticking).
2. The metering diaphragm is
damaged.
In either case the carburetor must be
removed and serviced.
• After completing test, open the vent
screw and pull the fuel line off the
elbow connector.
• Install the carburetor - see 10.2.1.
• Pull the carburetor off the studs
and detach the throttle rod (1)
from the throttle shaft (2) at the
same time.
Installation is a reversal of the
removal sequence.
Note:
Check that sleeve (in manifold)
and washer are in place before fitting
the carburetor.
Fit new mounting nuts and tighten
them down to 3.3 Nm (2.4 Ibf.ft).
• Remove the gasket and pump
diaphragm from the cover or
carburetor body.
Note:
The diaphragm and gasket
often stick to the cover or carburetor
body. If this is the case, take particular
care when separating them.
• Remove the carburetor
see 10.2.1.
• Unscrew and remove the fuel
pump end cover.
