Jonsered CS 2147 - Manual (Page 31)

English – 31
MAINTENANCE
Fine adjustment of the idle speed T
Adjust the idle speed with the T-screw. If it is necessary to re-
adjust, turn the T-screw clockwise while the engine is running,
until the chain starts to rotate. Then turn anti-clockwise until
the chain stops. When the idle speed is correctly adjusted the
engine should run smoothly in every position and the engine
speed should be safely below the speed at which the chain
starts to rotate.
High speed jet H
• The high speed jet H influences the power and engine
speed of the machine. If the high speed jet is set too rich
(H-jet screwed in too far) the machine will over-rev and this
will damage the engine. Run the machine at full throttle for
about 10 seconds. Then turn the H-jet 1/4 turn anti-
clockwise. Run the machine at full throttle for another 10
seconds or so and listen to the difference in the fast idle
speed. Repeat this procedure with the H-jet turned a
further 1/4 turn anti-clockwise.
• You have now run the machine at settings of H =
±
0, H=+1/
4, H=+1/2 relative to the basic settings. At full throttle the
engine has sounded different for each setting. The H-jet is
correctly adjusted when the machine burbles a little. If the
machine ”screams” then the machine is set too lean. If the
muffler emits a lot of smoke and the machine burbles a lot
then the setting is too rich. Turn the H-jet clockwise until
the setting sounds right
CAUTION! To ensure correct adjustment you should enlist
a qualified mechanic who has access to a tachometer.
The recommended maximum fast idle speed must not be
exceeded.
Correctly adjusted carburettor
When the carburettor is correctly adjusted the machine
accelerates without hesitation and burbles a little at full
throttle. It is also important that the chain does not rotate at
idle. If the L-jet is set too lean it may cause starting difficulties
and poor acceleration. If the H-jet is set too lean the machine
will have less power, poor acceleration and could suffer
damage to the engine. If the L and H-jets are set too rich it will
lead to acceleration problems or too low a working speed.
Starter
Changing a broken or worn starter cord
• Loosen the screws that hold the starter against the
crankcase and remove the starter.
• Pull out the cord approx. 30 cm and hook it into the notch
in the rim of the pulley. Release the recoil spring by letting
the pulley rotate slowly backwards.
• Undo the screw in the centre of the pulley and remove the
pulley. Insert and fasten a new starter cord to the pulley.
Wind approx. 3 turns of the starter cord onto the pulley.
Connect the pulley to the recoil spring so that the end of
the spring engages in the pulley. Fit the screw in the centre
of the pulley. Insert the starter cord through the hole in the
starter housing and the starter handle. Make a secure
knot in the end of the starter cord.
!
WARNING! Contact your service agent, if the
idle speed setting cannot be adjusted so that
the chain stops. Do not use the chain saw
until it has been properly adjusted or
repaired.
H
!
WARNING! When the recoil spring is wound
up in the starter housing it is under tension
and can, if handled carelessly, pop out and
cause personal injury. Always be careful
when changing the recoil spring or the
starter cord. Always wear protective
goggles.