Engine Management; Adjusting The Carburetor - Stihl MM 55 Instruction Manual

Engine Management

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.
MM 55, MM 55 C

Adjusting the Carburetor

General Information
The carburetor comes from the factory
with a standard setting.
This setting provides an optimum fuel-air
mixture under most operating
conditions.
Preparations
Shut off the engine.
N
Mount the MultiTool.
N
Check the air filter and clean or
N
replace if necessary.
Check the spark arresting screen
N
(not in all models, country-specific)
in the muffler and clean or replace if
necessary.
Standard Setting
L
Turn high speed screw (H)
N
counterclockwise as far as stop (no
more than 3/4 turn).
Turn the low speed screw (L)
N
clockwise as far as stop, then turn it
back 3/4 turn.
Adjusting Idle Speed
Carry out the standard setting.
N
Start and warm up the engine for
N
3 minutes.
English
15