Stihl MS 440 Service Manual

68 MS 440, MS 440 C
In the case of problems with the
carburetor or fuel supply system,
also check and clean or replace the
tank vent – b 12.5
The carburetor can be tested for
leaks with the carburetor and
crankcase tester 1106 850 2905.
– Remove the carburetor –
b 12.2.1
: Push the fuel line (1)
1110 141 8600 onto the
nipple (2) 0000 855 9200.
VA
143RA172
2 1
: Push the fuel line with nipple onto
the carburetor’s elbow connector.
VA
176RA264
: Push the fuel line with nipple onto
the carburetor’s elbow connector
1106 850 2905.
: Close the vent screw (1) on the
rubber bulb (2) and pump air into
the carburetor until the pressure
gauge (3) shows a reading of
VA
176RA265
2
1
3
approx. 0.8 bar (11.60 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). Remove to clean –
b 12.3.2
2. Metering diaphragm damaged,
replace if necessary – b 12.3.1
– After completing the test, open
the vent screw (1) and pull the
fuel line off the carburetor.
– Push the fuel hose onto the
elbow connector.
– Install the carburetor – b 12.2.1
Reassemble all other parts in the
reverse sequence.
– Remove the carburetor –
b 12.2.1
: Take out the screws (arrows).
– Remove the end cover.
– Carefully remove the gasket and
VA
176RA270
pump diaphragm from the end
cover.
: Carefully separate the diaphragm
and gasket.
– Examine the diaphragm for signs
of damage or wear, replace if
necessary.
VA
176RA272
12.2.2 Leakage Test 12.3 Servicing the Carburetor
12.3.1 Metering Diaphragm

Stihl MS 440 Specifications

General

Displacement	70.7 cc
Chain Pitch	3/8"
Ignition system	Electronic
Starter	Recoil starter
Vibration reduction	Anti-vibration system
Weight (without bar and chain)	6.4 kg
Fuel tank volume	0.73 L
Oil Capacity	0.36 L
Guide Bar Length	40-63 cm
Guide Bar Length (recommended)	40-71 cm (16-28 in)