Carburettor - Adjustment - Jonsered CS 2141 Workshop Manual

Repair instructions
3
Refi t the carburettor. Screw in the carburettor bolts
directly from behind without lifting the carburettor
assembly, tightening to a torque of 1–1.5 Nm. It is
important to hold the carburettor fl ange securely
when tightening the bolts to prevent the inlet mani-
fold from moving.
4
Push down the rear carburettor mounting into the
rubber bushings using a small screwdriver. Re-
move tool 502 54 17-01.
5
Refi t:
• cylinder, see special instructions
• silencer support (does not apply to CS 2141,
CS 2145, CS 2150)
• air fi lter
• HT lead
• cylinder cover
• after the test run retighten the silencer bolts to a
torque of 8–10 Nm
42
– English
Carburettor – adjustment
For instructions on adjusting the EPA carburettor
see appendix A.
Adjusting the carburettor involves adjusting the
engine to the local conditions e.g. climate, altitude,
fuel and type of two-stroke oil.
The carburettor is equipped with three adjustment
options.
L = Low speed jet
H = High speed jet
T = Idling adjustment screw
The L and H jets adjust the fuel fl ow to match
the airfl ow that the throttle valve opening allows.
Turning them clockwise makes the fuel/air mixture
weaker (less fuel in relation to the amount of air)
and turning them anti-clockwise makes the fuel/
air mixture richer. A weak mixture increases the
engine speed and a rich mixture decreases the
engine speed.
The T screw controls the throttle position when
idling. Turning the T screw clockwise gives faster
idling; turning it anti-clockwise lowers idling speed.
WARNING!
The guide bar, chain and clutch
cover must be fi tted before the
saw is started, otherwise the
clutch may fl y off and cause injury.
Basic settings and running in
During testing at the factory the carburettor is ad-
justed to the basic factory settings.
The factory settings are H = 1 turn and L = 1 turn.
To ensure that engine components receive ad-
equate lubrication (running in) the carburettor
should be set to a somewhat richer fuel mixture
for the chainsaw's fi rst 3-4 running hours. This
is done by adjusting the maximum speed to 6-
700 rpm less than the recommended maximum
speed.