Operation Manual

BR 450, BR 450 C
English
13
It may be necessary to correct the
adjustment of the throttle cable after
assembling the machine or after a
prolonged period of operation.
Adjust the throttle cable only when the
unit is completely and properly
assembled.
N Set the throttle trigger to the full
throttle position.
N Carefully rotate the screw in the
throttle trigger in the direction of the
arrow until you feel initial resistance.
Then rotate it another half turn in the
same direction.
Adjusting the Harness
N Pull the ends of the straps
downwards to tighten the harness.
Loosening the Harness
N Lift the tabs of the sliding adjusters.
N Adjust the harness so that the
backplate fits snugly and securely
against your back.
This engine is certified to operate on
unleaded gasoline and the STIHL two-
stroke engine oil at a mix ratio of 50:1.
Your engine requires a mixture of high-
quality gasoline and two-stroke air
cooled engine oil.
Use mid-grade unleaded gasoline with a
minimum octane rating of 89 ((R+M)/2)
and no more than 10% ethanol content.
NOTICE
Fuel with an octane rating below 89 may
increase engine temperatures. This, in
turn, increases the risk of piston seizure
and damage to the engine.
The chemical composition of the fuel is
also important. Some fuel additives not
only detrimentally affect elastomers
(carburetor diaphragms, oil seals, fuel
lines, etc.), but magnesium castings and
catalytic converters as well. This could
cause running problems or damage the
engine. For this reason STIHL
recommends that you use only quality
unleaded gasoline!
NOTICE
Gasoline with an ethanol content of
more than 10% can cause running
problems and major damage in engines
and should not be used.
For further details, see
www.STIHLusa.com/ethanol
The ethanol content in gasoline affects
engine speed – it may be necessary to
readjust the carburetor if you use fuels
with various ethanol contents.
Adjusting the Throttle Cable
002BA655 KN
Fitting the Harness
373BA003 KN
373BA004 KN
Fuel