Muffler/Spark; Arresting Screen; Leakage Test; Preparations - Stihl MS 270 User Manual

6 Engine
6.1 Muffler/Spark Arresting
Screen
Always check and, if necessary,
repair the fuel system, carburetor,
air filter and ignition system before
looking for faults on the engine.
Troubleshooting chart – see
2
1
Take out the screws (arrows).
– Remove the muffler.
Take out the screw (1), if fitted,
and pull out the spark arresting
screen (2).
Inspect spark arresting
screen (2) for damage, clean or
replace if necessary.
Reassemble in the reverse
sequence.
MS 270, MS 280
6.2

Leakage Test

Defective oil seals and gaskets or
cracks in castings are the usual
causes of leaks. Such faults allow
supplementary air to enter the
engine and upset the fuel-air
4.6. 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 crankcase can be checked
thoroughly for leaks with the
carburetor and crankcase tester
and the vacuum pump.
6.2.1

Preparations

1
– Remove the shroud –
– Remove the decompression
valve, if fitted – see 6.8.
Install plug (1) 1122 025 2200
and tighten down to 25 Nm.
– Make sure spark plug is properly
tightened down – see
– Remove the muffler –
1 2
Remove the heat shield (1) from
the muffler (2).
see 6.4.
3.5.
see 6.1.
33