Stihl Fs 450 K Manual

30 English / USA
FS 300, FS 350, FS 400, FS 450, FS 480 If the engine still does not start:
:Move the slide control to 0 c
:Pull off the spark plug boot (5).
:Unscrew and dry off the spark plug.
:Open the throttle wide.
:Crank the engine several times with 
the starter to clear the combustion 
chamber.
:Refit the spark plug. Connect the 
spark plug boot (press it down 
firmly).
:Move the slide control to START.
:Set the choke knob to e –
even if the engine is cold.
:Now start the engine.Throttle cable...

31 FS 300, FS 350, FS 400, FS 450, FS 480English / USA
Dirty air filters reduce engine power, 
increase fuel consumption and make 
starting more difficult.
If there is a noticeable loss of engine 
power
:Turn the choke knob to g
:Press in the tab (1).
:Pull off the filter cover (2). 
:Clean away loose dirt from inside 
the filter cover and around the filter.:Remove the filter element (3) and 
inspect it – replace if dirty or 
damaged.
:Fit the air filter in the cover.
:Push the filter cover into...

32 English / USA
FS 300, FS 350, FS 400, FS 450, FS 480 Exhaust emissions are controlled by the 
design of the fundamental engine 
parameters and components (e.g. 
carburation, ignition, timing and valve or 
port timing) without the addition of any 
major hardware.
General InformationThe carburetor comes from the factory 
with a standard setting.
This setting provides an optimum fuel-air 
mixture under most operating 
conditions.
With this carburetor it is only possible to 
adjust the high speed screw...

33 FS 300, FS 350, FS 400, FS 450, FS 480English / USA
Adjusting Idle SpeedEngine stops while idling 
:Carry out standard setting with the 
low speed screw (L).
:Turn the idle speed screw (LA) 
clockwise until the engine runs 
smoothly – the cutting tool must not 
rotate.
Cutting tool rotates when engine is 
idling
:Turn the idle speed screw (LA) 
counterclockwise until the cutting 
tool stops rotating – then turn the 
screw about another half to one full 
turn in the same direction from that...

34 English / USA
FS 300, FS 350, FS 400, FS 450, FS 480 At the end of the cold season:
:Remove the special air filter (2) for 
winter operation and install the 
standard filter (1) in its place.
:Push the cover (3) into the summer 
position (lower illustration).
Switching on handle heating (special 
option)
:Move the switch in the left handle 
to 
Z – 
move the switch back to O to turn off 
the heating.
If the handle temperature feels too high 
– move switch to O.
There is no risk of overheating during...

35 FS 300, FS 350, FS 400, FS 450, FS 480English / USA
If engine is down on power, difficult to 
start or runs poorly at idling speed, first 
check the spark plug.
:Remove spark plug – see Starting / 
Stopping the Engine.
:Clean dirty spark plug.
:Check electrode gap (A) and 
readjust if necessary – see 
Specifications.
:Use only resistor type spark plugs 
of the approved range.
Rectify problems which have caused 
fouling of spark plug: 
:Too much oil in fuel mix.
:Dirty air filter.
:Unfavorable running...

36 English / USA
FS 300, FS 350, FS 400, FS 450, FS 480 Use STIHL gear lubricant for 
brushcutters (see Guide to Using this 
Manual).
:Check grease level about every 
100 hours of operation.
:Unscrew the filler plug (1).
:If no grease can be seen on the 
inside of the filler plug, screw the 
tube of lubricant (2) into the filler 
hole.
:Squeeze grease into the gear 
housing – till 1/5 oz (5 g).
Do not completely fill the gear 
housing with grease.
:Refit the filler plug and tighten it 
down firmly....

37 FS 300, FS 350, FS 400, FS 450, FS 480English / USA
:Thread the rope through the rotor 
and secure it in the rotor with a 
simple overhand knot.
:Lubricate the rope rotor bearing 
bore with non-resinous oil (Special 
Accessories).
:Slide rotor onto starter post – turn it 
back and forthe until the loop of the 
rewind spring engages.
:Fit the pawl (4) and washer (3), and 
press the spring clip (2) into 
position.
The spring clip must point counter- 
clockwise and engage the peg on 
the pawl.
Tensioning...

38 English / USA
FS 300, FS 350, FS 400, FS 450, FS 480 :Place spring with frame in position 
– check that outer spring loop (8) is 
correctly seated.
:Use a suitable tool to push the 
spring into the housing. Apply tool 
through the openings (see arrows). 
The frame slips off in this process.
If the spring pops out and uncoils during 
installation: Refit it in the spring housing 
in the counterclockwise direction – start 
outside and work inward.
:Fit the screw.
:Install the rope rotor as described in...

39 FS 300, FS 350, FS 400, FS 450, FS 480English / USA
Never attempt to straighten or weld 
a bent or cracked cutting tool – it 
might shatter and cause serious or 
fatal injury.
:Resharpen frequently, take away as 
little material as possible – two or 
three strokes of the file are usually 
enough.
To avoid out-of-balance:
:Resharpen the cutters (1) uniformly 
– do not alter the contour of the 
parent blade (2) in any way.
:After resharpening about 5 times, 
have blade checked on STIHL 
balancer*.
Grass...