Stihl MS 390 Instruction Manual page 43

English / USA
Standard setting
: Shut off the engine.
: Check the air filter and replace if
necessary.
: Check the spark arresting screen
and clean or replace as necessary.
: Turn the high speed adjusting screw
(H) counterclockwise up to the stop,
3
i.e. / turn from max. lean setting.
4
: Turn the low speed adjusting screw
(L) clockwise up to the stop – then
back off the screw one quarter of a
turn.
42
Adjusting idle speed
Engine stops while idling
: Turn the idle speed adjusting screw
(LA) clockwise until chain begins to
run – then back off the screw one
quarter of a turn.
Chain runs when engine is idling
: Turn the idle speed adjusting screw
(LA) counterclockwise until chain
stops running – then turn screw
another quarter turn in the same
direction.
If the chain continues moving when
the engine is idling, have your saw
checked and repaired by your servicing
dealer.
Erratic idling behavior, poor
acceleration
Idle setting is too lean.
: Turn the low speed adjusting screw
(L) counterclockwise until engine
runs and accelerates smoothly.
MS 290, MS 310, MS 390