Stihl Km 90 R Owners Manual

KM 90 R
English
9
WARNING
Never test the ignition system with the 
ignition wire boot removed from the 
spark plug or with a removed spark plug, 
since uncontained sparking may cause 
a fire.
WARNING
Do not operate your power tool if the 
muffler is damaged, missing or modified. 
An improperly maintained muffler will 
increase the risk of fire and hearing loss. 
Your muffler is equipped with a spark-
arresting screen to reduce the risk of 
fire; never operate your power tool if the 
screen is missing,...

KM 90 R
English
10The following STIHL KombiTools may 
be mounted on the KombiEngine:
Approved KombiTools
HT-KMBF-KM
464BA025 KN
KW-KMKB-KM
FH-KMFSB-KMBG-KM
FBD-KM
FS-KMFS-KM
FCS-KMFCB-KM
.RPEL7RRO
WKHEDUULHUEDURQWKHORRSKDQGOH
VXSSOLHGZLWKWKHPDFKLQHPXVWEH
XVHG

KM 90 R
English
11 A barrier bar is supplied with the 
machine. Attach the barrier bar to the 
loop handle.
NInsert square nuts (1) in the barrier 
bar (2) – the holes must line upNInsert the clamp(3) in the loop 
handle (4) and position them 
together on the shaft (5)
NPosition clamp (6)
NPosition barrier bar (2) – note 
position!
NLine up the holes
NInsert bolts (7) in the holes – and 
screw them into the barrier bar as 
far as possibleNFit the loop handle (4) at a distance 
of (A) approx. 20 cm (8 in)...

KM 90 R
English
12 A properly adjusted throttle cable is the 
precondition for correct operation in the 
starting throttle, idle and full throttle 
positions.
Adjust the throttle cable only when the 
machine is completely and properly 
assembled.
NUse a suitable tool to push the slide 
to the end of the slot (see 
illustration).
NPress down the trigger lockout (1) 
and squeeze the throttle trigger (2) 
(full throttle position) – this sets the 
throttle cable correctly.This engine is certified to operate...

KM 90 R
English
13 The container should be kept tightly 
closed in order to limit the amount of 
moisture that gets into the mixture.
The machine’s fuel tank should be 
cleaned as necessary.
Fuel mix ages
Only mix sufficient fuel for a few days 
work, not to exceed 30 days of storage. 
Store in approved fuel-containers only. 
When mixing, pour oil into the container 
first, and then add gasoline. Close the 
container and shake it vigorously by 
hand to ensure proper mixing of the oil 
with the fuel....

KM 90 R
English
14
Controls
1Throttle trigger lockout
2Throttle trigger
3Slide control
Positions of slide control
4STOP-0– engine off – ignition is 
switched off
5F– normal run position – the engine 
is running or can start
6START – ignition is switched on – 
the engine can startSymbol on slide control
7h – stop symbol and arrow. To stop 
the engine, push the slide control in 
the direction of the arrow on the stop 
symbol (h) to STOP-0.
Starting
NPress down the trigger lockout lever 
and squeeze the...

KM 90 R
English
15 NMake sure you have a firm footing, 
either standing, stooping or 
kneeling.
NHold the unit firmly on the ground 
with your left hand and press down 
– thumb under the fan housing – do 
not touch the throttle trigger or 
trigger lockout.
NOTICE
Do not stand or kneel on the drive tube.
NHold the starter grip with your right 
hand.
NPull the starter grip slowly until you 
feel it engage and then give it a brisk 
strong pull.
NOTICE
Do not pull out the starter rope all the 
way – it might...

KM 90 R
English
16
During break-in period
A factory-new machine should not be 
run at high revs (full throttle off load) for 
the first three tank fillings. This avoids 
unnecessary high loads during the 
break-in period. As all moving parts 
have to bed in during the break-in 
period, the frictional resistances in the 
engine are greater during this period. 
The engine develops its maximum 
power after about 5 to 15 tank fillings.
During Operation
After a long period of full throttle 
operation, allow...

KM 90 R
English
17 The carburetor has been set at the 
factory to provide an optimum fuel-air 
mixture under most operating 
conditions.
Adjusting Idle Speed
Engine stops while idling
NWarm up the engine for about 
3 minutes.
NTurn the idle speed screw (LA) 
slowly clockwise until the engine 
runs smoothly – the cutting 
attachment must not rotate.
Attachment runs when engine is idling
NTurn the idle speed screw (LA) 
slowly counterclockwise until the 
cutting attachment stops running 
and then turn the...

KM 90 R
English
18 If engine is down on power, difficult to 
start or runs poorly at idling speed, first 
check the spark plug.
Fit a new spark plug after approx. 100 
operating hours or earlier if the 
electrodes are badly eroded.
Wrong fuel mix (too much engine oil in 
the gasoline), a dirty air filter and 
unfavorable running conditions (mostly 
at part throttle etc.) affect the condition 
of the spark plug. These factors cause 
deposits to form on the insulator nose 
which may result in trouble in...