Adjusting The Throttle Cable; Fuel - Stihl HL 90 Instruction Manual

1
3
2
1
Loosen the clamp screws (1).
N
Push the gearbox (2) onto the drive
N
tube (3) – turn it back and forth at
the same time until the end of the
drive tube is no longer visible in the
slot (arrow) – then push fully home
as far as stop.
Line up the gearbox on the drive
N
tube so that the machine support on
the engine points down and the
blades are horizontal.
Tighten down the clamp screws (1)
N
firmly.
HL 90 K

Adjusting the Throttle Cable

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.
Use a suitable tool to push the slide
N
to the end of the slot (see
illustration).
1
2
Press down the trigger lockout (1)
N
and squeeze the throttle trigger (2)
(full throttle position) – this sets the
throttle cable correctly.

Fuel

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.
Fuel with a lower octane rating 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 even
damage the engine. For this reason
STIHL recommends that you use only
high-quality unleaded gasoline!
Gasoline with an ethanol content of
more than 10% can cause running
problems and major damage in engines
and should not be used.
The ethanol content in gasoline affects
engine running speed – it may be
necessary to readjust the carburetor if
you use fuels with various ethanol
contents.
WARNING
To reduce the risk of personal injury
from loss of control and / or contact with
the running cutting tool, do not use your
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