Stihl 029, 039 - 4.2.2 Pressure Test

STIHL 029, 039 25
4.2.2 Pressure Test
- Check to see that the pin in the
test flange is in bore No. 1 and
fit it if necessary.
- Fit the test flange in place of the
carburetor.
Important: When fitting the test
flange, make sure the pin is
properly located in the impulse
hose.
- Fit the flange in place of the
muffler.
- Push the sleeves over the mounting
screws. Fit the nuts and tighten
them firmly.
Note: Sealing plate must completely
fill the space between the two
mounting screws.
- Remove carburetor - see 11.2.
- Set the piston to top dead center
(T.D.C.). This can be checked
through the inlet port.
- Connect tester's pressure hose
to nipple on test flange.
- Make sure the spark plug is
properly tightened down before
starting the test.
- Close the vent screw on the
rubber bulb.
- Use rubber bulb to pump air into
the engine housing until the gauge
shows a pressure of 0.4 bar
(5.8 psi). If this pressure remains
constant for at least 20 seconds,
the engine housing is airtight.
Top:
Flange 1123 855 4200 fitted in position
Bottom:
Test flange 1128 850 4200
Top:
1 = Bore No. 1
2 = Bore No. 2
Bottom:
Test flange fitted in position
(pin in impulse hose)
Top:
Tester's pressure hose fitted on test flange nipple
Bottom:
Closing the vent screw