Jonsered CS 2171WH manual Carburettor without movement limiters, Low speed jet L, High speed jet H

MAINTENANCE

Low speed jet L

Turn the low speed jet L clockwise until it stops. If the engine accelerates poorly or idles unevenly, turn the low speed jet L anticlockwise until good acceleration and idling are achieved.

CAUTION! If the chain rotates while idling the T-screw must be turned anti-clockwise until the chain stops.

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.

WARNING! Contact your servicing dealer, 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.

High speed jet H

At the factory the engine is adjusted at sea level. When working at a high altitude or in different weather conditions, temperatures and atmospheric humidity, it may be necessary to make minor adjustments to the high speed jet.

CAUTION! If the high speed jet is screwed in too far, it may damage the piston/cylinder.

When test run at the factory, the high speed jet is set so that the engine satisfies the applicable legal requirements at the same time as achieving maximum performance. The carburettor’s high speed jet is then locked using a limiter cap in the fully screwed out position. The limiter cap limits the potential to adjust the high speed jet to at most half a turn.

CAUTION! There is an integrated speed governor in the ignition system that limits the maximum speed to 13600 rpm. The maximum speed will not exceed 13600 rpm when the high speed jet is adjusted (screwed in). When the speed governor is activated, you will get the same sound experience as when the chain saw 4-cycles.

To adjust the carburettor correctly you should contact a mechanic with access to a rev counter.

CAUTION! As the spark is cut off, the rev counter does not show speeds higher than 13600 rpm.

Correctly adjusted carburettor

When the carburettor is correctly adjusted the machine accelerates without hesitation and 4-cycles 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.

Carburettor without movement limiters

Function, Basic settings, Fine adjustment

WARNING! Do not start the chain saw unless

!the bar, chain and clutch cover (chain brake) are fitted, otherwise the clutch may come loose and cause personal injury.

Function

•The carburettor governs the engine’s speed via the 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.

•Adjusting the carburettor means that the engine is adapted to local operating conditions, e.g. climate, altitude, petrol and the type of 2-stroke oil.

•The carburettor has three adjustment controls:

-L = Low speed jet

-H = High speed jet

-T = Idle adjustment screw

TH

L

•The T-screw regulates the throttle setting at idle speed. If the T-screw is turned clockwise this gives a higher idle speed; turning it anti-clockwise gives a lower idle speed.

Basic settings and running in

The basic carburettor settings are adjusted during testing at the factory. The basic settings are H = 1 turn and L = 1 turn. To provide the engine’s components with good initial lubrication (during running in) the carburettor should be set for a richer fuel mixture for the first 3-4 hours that the chain saw is in use. To do this, adjust the fast idle speed to 600-700 rpm below the recommended maximum fast idle speed.

If you are unable to check the fast idle speed using a tachometer the H-jet should not be set for a leaner mixture than given in the basic settings. The recommended maximum fast idle speed must not be exceeded. CAUTION! If the chain rotates while idling the T-screw must be turned anti- clockwise until the chain stops.

30 – English