Operation Manual

BG 56, BG 56 C, BG 66, BG 66 C, BG 86, BG 86 C, SH 56, SH 56 C, SH 86, SH 86 C
English
18
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.
The 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 within fine
limits.
Standard Setting
N Shut off the engine.
N Turn high speed screw (H)
counterclockwise (no more than a
3/4 turn) as far as stop.
N Turn the low speed screw (L)
carefully home as far as stop and
then open it 1 full turn.
Fine Tuning for Operation in
Mountains or at Sea Level
A slight correction of the setting may be
necessary if engine power is not
satisfactory when operating at high
altitude or at sea level.
N Check the air filter and clean it if
necessary.
N Warm up the engine.
At high altitude
N Turn high speed screw (H)
clockwise (leaner) – no further than
stop.
At sea level
N Turn high speed screw (H) slightly
counterclockwise (richer) – no
further than stop.
Adjusting Idle Speed
It is usually necessary to change the
setting of the idle speed screw (LA) after
every correction to the low speed
screw (L).
Engine stops while idling
N Check the standard setting.
N Turn the idle speed screw (LA)
clockwise until the engine runs
smoothly.
Erratic idling behavior
If acceleration is poor even though the
standard setting is correct, the idle
setting is too rich:
Engine Management Adjusting the Carburetor
295BA076 KN
295BA077 KN