Stihl 020 T

STIHL 020 T 17
4.2.2 Pressure Test
4.2.1 Preparations
• Remove the muffler – 4.1.
• Set the piston to top dead center
(T.D.C.). This can be checked
through the exhaust port.
• Fit flange (1) with sleeves (2)
and screws (3) on cylinder
exhaust port. Do not tighten
down yet.
• Slide the sealing plate (4)
between the flange and cylinder
and tighten down the mounting
screws.
Note: The sealing plate must
completely fill the space between
the two mounting screws.
• Remove the carburetor –
see 10.2.1.
• Check that washer (1) and
sleeve (2) are in position.
• Connect tester's pressure hose to
nipple on test flange.
• Make sure the spark plug is
properly tightened down.
• Remove screw (1) from the test
flange (2).
• Close the vent screw (1) on the
rubber bulb.
• Use rubber bulb to pump air into
the crankcase until the gauge
indicates a pressure of 0.5 bar
(7.25 psi). If this pressure remains
constant for at least 20 seconds,
the crankcase is airtight.
• Fit the test flange on the
carburetor studs.
• Fit nuts (1) and tighten down
firmly.
If the flange has only three holes,
drill a fourth hole as shown in the
drawing.