Stihl KM 90 R User Manual

KM 90 R
English
20
Approx. value
Turn the high speed screw (H) approx.
1/4 turn per 1000 m (3300 ft) difference
in elevation
N Carry out standard adjustment for
idle speed screw (L)
N Let the engine warm up for
approx. 3 min
N Open the throttle fully
In the mountains
N Turn the high speed screw (H)
clockwise (leaner) – until there is no
longer a noticeable increase in
speed – max. as far as possible
At sea level
N Turn the high speed screw (H)
counterclockwise (richer) – until
there is no longer a noticeable
increase in speed – max. as far as
possible
It is possible that the maximum speed is
already obtained at the standard setting.
Setting the idle speed
Whenever the low speed screw (L) has
been adjusted, it is usually also
necessary to adjust the idle speed
screw (LA).
N Let the engine warm up for
approx. 3 min
Engine stops when idling
N Slowly turn idle speed screw (LA)
clockwise until the engine runs
smoothly – the working tool must
not move
Cutting attachment turns when idling
N Turn the idle speed screw (LA)
counterclockwise until the working
tool stops moving – then turn
another 1/2 to 3/4 turn in the same
direction
Erratic idling behavior, engine stalls
despite correction of LA-setting, poor
acceleration
The idle setting is too lean:
N Turn the low speed screw (L)
counterclockwise until the engine
runs and accelerates smoothly – but
no further than the stop
Erratic idling behavior
The idle setting is too rich:
N Turn the low speed screw (L)
clockwise until the engine runs and
accelerates smoothly – but no
further than the stop
In some countries the muffler is
equipped with a spark arresting screen.
N If the engine is down on power,
check the spark arresting screen in
the muffler.
N Wait for the muffler to cool down.
N Move the slide control to STOP-0.
N Take out the screw (1).
N Take out the screws (2) and remove
the shroud (3).
If the working tool continues to
keep moving in idle even after
adjustment, have the machine
checked by a servicing dealer.
Spark Arresting Screen in
Muffler
249BA059 KN
1
2
3
2
249BA060 KN

Stihl KM 90 R Specifications

General

Engine Type	2-stroke
Displacement	28.4 cc
Sound Pressure Level	96 dB(A)
Sound Power Level	107 dB(A)
Powerhead Weight	4.4 kg
Weight	4.4 kg (9.7 lbs)
Engine Power	0.8 kW
Fuel Tank Volume	0.44 l
Recommended Oil Mix	50:1 with STIHL HP Ultra oil