Spark Arresting Screen In Muffler - Stihl MS 290 Instruction Manual

English
Setting the idle speed
Engine stops when idling
Set low speed screw to standard
N
setting
Turn the idle speed adjusting
N
screw (LA) clockwise until the saw
chain begins to run – then turn it
back 1/4 turn.
Saw chain rotates at idle speed
Set low speed screw to standard
N
setting
Turn the idle speed screw (LA)
N
counterclockwise until the chain
stops running – then turn another
1/4 turn in the same direction.
If the saw chain continues to keep
rotating in idle even after adjustment,
have it checked by a servicing dealer.
Speed erratic when idling; poor
acceleration (despite low speed screw =
standard setting)
Idle setting too lean – turn low speed
N
screw (L) counterclockwise until the
engine runs smoothly and
30
accelerates correctly – with
carburetors with L = 1/4 max. up to
the stop
Whenever the low speed screw (L) has
been adjusted, at least one adjustment
must also be made on the idle speed
adjusting screw (LA).
Correcting the carburetor setting for use
at high altitudes
The setting may have to be marginally
corrected if engine performance is
unsatisfactory at high altitudes:
Check the standard setting
N
Let the engine warm up
N
Turn the high speed screw (H)
N
slightly clockwise (leaner) – for
carburetors with H = 3/4 max. up to
the stop
If you make the setting too lean it will
increase the risk of engine damage
through lack of lubrication and
overheating.
Spark Arresting Screen in
Muffler
In some countries, the muffler is fitted
with a spark arresting screen.
If engine performance deteriorates,
N
check the spark arresting screen in
the muffler
Let the muffler cool down
N
1
1
1
Unscrew and remove the nuts (1)
N
3
Remove the cover (2)
N
Remove the spark arresting
N
screen (3)
Clean the dirty spark arresting
N
screen, replace if damaged or
heavily carbonized
Refit the spark arresting screen
N
Reinstall cover
N
MS 290, MS 310, MS 390
2