Leakage Test; Preparations - Stihl 019 T User Manual

4.4

Leakage Test

Defective oil seals, diaphragms and
gaskets or cracks in castings or the
spacer flange cause leaks. Such
faults allow supplementary air to
enter the engine and thus upset the
fuel-air mixture.
This makes adjustment of the
prescribed idle speed difficult, if not
impossible.
Moreover, the transition from idle
speed to part or full throttle is not
smooth.
The engine housing can be checked
thoroughly for leaks with the
carburetor and crankcase tester and
the vacuum pump.
STIHL 019 T
4.4.1

Preparations

- Remove the carburetor - see 1 0.5.2.
- Set the piston to top dead center
(T.D.C.). This can be checked
through the spark plug hole.
- Remove the air baffle - see 10.6.
• Fit the spark plug and tighten
down to 25 Nm (18.5 Ibf.ft).
• Back off muffler mounting screws
halfway.
• Fit the sealing plate (1)
0000 855 8106 between muffler
and cylinder.
Note: The sealing plate must
completely cover the exhaust port.
- Tighten the screws moderately.
Important: Do not overtighten the
screws since the sealing plate may
otherwise be damaged.
• Fit new gasket on spacer flange.
15