Carburettor Settings - Husqvarna 125C Workshop Manual

3
L
24
Fuel system

Carburettor settings

T
Function
The carburettor has the task of supplying a combustible fuel/air mixture to the
cylinder.
H
The amount of this mixture is controlled by the throttle.
The mixture's composition of fuel and air is controlled by means of the adjustable
"H" and "L" needles.
The needles must be correctly adjusted in order for the engine to give maximum
power at different speeds, run steadily while idling and to react quickly when
accelerating.
The setting of the carburettor can vary a little depending on the humidity, tempera-
ture and air pressure.
L = Low speed needle
H = High speed needle
T = Idle adjustment screw
• The fuel quantity in relation to the air flow permitted by the throttle opening is
adjusted by the L and H jets. Turning the needles clockwise gives a leaner fuel
mixture (less fuel) and turning them anticlockwise gives a richer fuel mixture
(more fuel). A leaner mixture gives higher revs while a richer mixture gives less
revs.
• The T-screw regulates the position of the throttle while the engine is idling.
Turning the screw clockwise gives a higher idling speed while turning it anti-
clockwise gives a lower idling speed.
WARNING!
When testing the engine in connection with carburettor
adjustment, the clutch and clutch cover must be mounted
together with the shaft and angle gear under all circumstances
Otherwise there is a risk of the clutch becoming loose resulting in
serious personal injury.
Assemble the throttle in the reverse
order as set out for dismantling.
Pay attention to the following:
1. Check that the short-circuit cables
and the throttle cable (E) are
inserted in the cable channel.
2. Make sure that the metal sleeve's
collar (F) on the throttle cable is
seated in its slot.
3. Check that the return spring (G) is
positioned correctly.
The above also applies to throttles
without the lock for unintentionally
activation with the exception of its
specific parts.