MAINTENANCE
High speed jet HY The L and H-jets are used to adjust the supply of fuel to
match the rate that air is admitted, which is controlled with
At the factory the engine is adjusted at sea level. When the throttle. If they are screwed clockwise the air/fuel ratio
working at a high altitude or in different weather becomes leaner (less fuel) and if they are turned anti-
conditions, temperatures and atmospheric humidity, it clockwise the ratio becomes richer (more fuel). A lean
may be necessary to make minor adjustments to the high mixture gives a higher engine speed and a rich mixture
speed jet.gives a lower engine speed.
CAUTION! If the high speed jet is screwed in too far, it Y The T-screw regulates the throttle setting at idle speed. If
may damage the piston/cylinder.the T-screw is turned clockwise this gives a higher idle
When test run at the factory, the high speed jet is set so that speed; turning it anti-clockwise gives a lower idle speed.
the engine satisŢes the applicable legal requirements at the
same time as achieving maximum performance. The Basic settings and running in
carburettorOs high speed jet is then locked using a limiter cap
in the fully screwed out position. The limiter cap limits the The basic carburettor settings are adjusted during testing at
the factory.
potential to adjust the high speed jet to at most half a turn.
The basic settings are H = 1 turn and L = 1 turn. To provide
Correctly adjusted carburettorthe engineOs components with good initial lubrication (during
running in) the carburettor should be set for a richer fuel
When the carburettor is correctly adjusted the machine mixture for the Ţrst 3-4 hours that the chain saw is in use. To
accelerates without hesitation and 4-cycles a little at full do this, adjust the fast idle speed to 600-700 rpm below the
throttle. It is also important that the chain does not rotate at recommended maximum fast idle speed.
idle. If the L-jet is set too lean it may cause starting difŢculties If you are unable to check the fast idle speed using a
and poor acceleration. If the H-jet is set too lean the machine
will have less power, poor acceleration and could suffer tachometer the H-jet should not be set for a leaner mixture
than given in the basic settings. The recommended maximum
damage to the engine.fast idle speed must not be exceeded.
CAUTION! If the chain rotates while idling the T-screw
Carburettor without movement
must be turned anti-clockwise until the chain stops.
limiters
Rec. idle speed: 2700 rpm
Fine adjustment
HWhen the machine has been �run-in� the carburettor should L
be Ţnely adjusted. The Ţne adjustment should be carried out
by a qualiŢed person. First adjust the L-jet, then the idling
screw T and then the H-jet.
The recommended engine speeds are as follows:
Max. fast idle speed, rpmIdle speed, rpm
357XP 140002700
Y The carburettor governs the engineOs speed via the 359135002700
throttle control. Air and fuel are mixed in the carburettor.
The air/fuel mixture is adjustable. Correct adjustment is
essential to get the best performance from the machine.Conditions
Y The satisfactory operation of a catalytic converter Y Before any adjustments are made the air Ţlter should be
depends, among other factors, on the correct adjustment clean and the cylinder cover Ţtted. Adjusting the
of the carburettor. Carefully follow the instructions below, carburettor while a dirty air Ţlter is in use will result in a
using a tachometer as an aid.leaner mixture next time the Ţlter is cleaned. This can give
Y Adjusting the carburettor means that the engine is rise to serious engine damage.
adapted to local operating conditions, e.g. climate, Y Carefully turn the L and H-jets clockwise as far as they will
altitude, petrol and the type of 2-stroke oil.go. Now turn the jets one turn anti-clockwise. The
carburettor is now set to H = 1 and L = 1.
Y The carburettor has three adjustment controls:
Y Now start the machine according to the starting
- L = Low speed jet
instructions and let it warm up for 10 minutes.
- H = High speed jetY Place the machine on a �at surface so that the bar points
- T = Idle adjustment screwaway from you and so that the bar and chain do not come
into contact with the surface or other objects.
LH
T
30 � English |
ACEC
