Stihl MS 192 T Manual page 28

8. Engine
8.1 Muffler / Spark Arresting
Screen
Check and if necessary repair the
fuel supply, carburetor, air filter and
ignition system before looking for
faults on the engine.
– Troubleshooting, b 8.1
– Remove the sprocket cover and
bar and chain, b 5.1
: Remove the screw (arrow).
1
2
: Remove the cover plate (2) and
spark arresting screen (1) if fitted.
– Clean the spark arresting screen
(1) or replace if necessary.
MS 192 T
: Take out the screws (arrows).
– Remove and examine the
muffler, replace if necessary.
– Clean the sealing faces.
A gasket is not fitted between
muffler and cylinder.
– Reassemble parts in reverse
order.
8.2 Leakage test
Defective oil seals and gaskets or
cracks in housing are the usual
causes of leaks. Such faults allow
supplementary air to enter the
engine and 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.
Always start with the vacuum test
and then continue with the pressure
test.
The crankcase can be thoroughly
checked for leaks with the
carburetor and crankcase tester
and the vacuum pump.
27