Chainsaw User Manual
42
English / USA
MS 290, MS 310, MS 390
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,
i.e. 
3
/
4
 turn from max. lean setting.
: Turn the low speed adjusting screw 
(L) clockwise up to the stop – then 
back off the screw one quarter of a 
turn.
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.
H
L
LA
139BA013 KN
4
L
H
3
1
/
4
/
H
L
LA
139BA013 KN
4
L
H
3
1
/
4
/










