Carburetor; Leakage Test - Stihl 4141 Series Manual

9.2

Carburetor

9.2.1

Leakage Test

Troubleshooting chart - see
"Standard Repairs, Trouble-
shooting" handbook.
Important:
In the event of trouble with the
carburetor or the fuel supply
system, always check and clean the
tank vent - see 9.6.
The carburetor can be tested for
leaks with the carburetor and
crankcase tester 1106 850 2905.
– Remove the air filter cover - see
9.1.
Pull fuel hoses off carburetor
elbow connectors.
2 1
Attach hose (1) 1110 141 8600 to
one end of nipple (2)
0000 855 9200 and tester's
pressure hose to other end.
34
Push the hose (with nipple and
tester) onto the carburetor's front
elbow connector.
Close vent screw (1) on rubber
bulb.
Use rubber bulb to pump air into
the carburetor until gauge
indicates a pressure of 0.8 bar
(11.5 psi).
If this pressure remains constant,
the carburetor is airtight. However, if
the pressure 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. Metering diaphragm damaged.
In either case the carburetor must
be serviced.
– After completing test, open the
vent screw and pull the pressure
hose off the elbow connector.
– Repeat the leakage test with the
hose attached to the carburetor's
rear elbow connector.
If there is any loss of pressure,
service the carburetor.
After completing the repairs, repeat
the leakage test.
1
Series 4141 Powerhead