Jonsered CS 2147 manual Maintenance, Carburettor

Page 30

MAINTENANCE

Carburettor

Your Jonsered product has been designed and manufactured to specifications that reduce harmful exhaust fumes. The engine will be run in after it has used 8-10 tanks of fuel. To ensure that the engine runs at peak performance and produces as little harmful exhaust fumes as possible after the running-in period, ask your dealer/service workshop (which has a rev counter for this purpose) to adjust your carburettor.

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

LH

T

•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 the throttle. If they are screwed clockwise the air/fuel ratio becomes leaner (less fuel) and if they are turned anti- clockwise the ratio becomes richer (more fuel). A lean mixture gives a higher engine speed and a rich mixture gives a lower engine speed.

•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.

WARNING! The catalytic converter muffler

!gets very hot during and after use. This also applies during idling. Be aware of the fire hazard, especially when working near flammable substances and/or vapours.

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 max. 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 max. fast idle speed must not be exceeded.

Fine adjustment

When the machine has been ”run-in” the carburettor should be finely adjusted. The fine adjustment should be carried out by a qualified person. First adjust the L-jet, then the idling screw T and then the H-jet.

 

Max. fast idle speed, rpm

Idle speed, rpm

CS 2147

14200

2700

CS 2152

13000

2700

Changing the type of fuel

Fine tuning may be required if the chain saw, after changing the type of fuel, performs differently with regard to starting, acceleration, max. speed, etc.

Conditions

•Before any adjustments are made the air filter should be clean and the cylinder cover fitted. Adjusting the carburettor while a dirty air filter is in use will result in a leaner mixture next time the filter is cleaned. This can give rise to serious engine damage.

•Carefully turn the L and H-jets clockwise as far as they will go. Now turn the jets one turn anti-clockwise. The carburettor is now set to H = 1 and L = 1.

•Now start the machine according to the starting instructions and let it warm up for 10 minutes. CAUTION!

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

•Place the machine on a flat surface so that the bar points away from you and so that the bar and chain do not come into contact with the surface or other objects.

Low speed jet L

+ 1/4

L

Try to find the highest idle speed by turning the low speed jet L clockwise then anti-clockwise. When the highest speed has been found, turn the low speed jet L 1/4 turn anti-clockwise.

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

30 – English

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Contents Operator′s manual KEY to Symbols Key to symbolsContents Safety Instructions Machine′s safety equipmentPersonal protective equipment Chain brake and hand guard Chain catcher Stop switchThrottle lock Right hand guardMuffler Checking brake band wearChecking the hand guard Throttle lock Checking the inertia brake releaseChecking the brake trigger Chain catcherGeneral rules Stop switchCutting equipment Vibration damping systemChain Cutting equipment designed to minimise kickbackBar Some terms that describe the bar and chainSharpening your chain and adjusting raker clearance General information on sharpening cutting teethWith a badly sharpened chain Tensioning the chain General advice on setting raker clearanceSetting the raker clearance Sharpening cutting teethFilling with chain oil Lubricating cutting equipmentChain oil Checking chain lubricationChecking wear on cutting equipment Lubricating the bar tip sprocketNeedle bearing lubrication Chain drive sprocketHow to avoid kickback What is kickback?Do not let go of the handles General safety precautions Fuel safety StartingBasic safety rules General working instructionsTransport and storage Terms Basic cutting techniqueGeneral CuttingSafe distance Tree felling techniqueLimbing Felling directionDirectional cuts Clearing the trunk and preparing your retreatFelling Felling cutCutting the trunk into logs Freeing a trapped tree General adviceFreeing a tree that has fallen badly Cutting trees and branches that are in tensionWhat is WHAT? What is what on the chain saw?Fitting a spike bumper AssemblyFitting the bar and chain Working with the chainFuel Handling FuelFollowing applies to chain saws with catalytic converters Chain oil FuellingCold engine Starting and StoppingStarting and stopping Warm engineStopping Maintenance CarburettorStarter Fine adjustment of the idle speed TCorrectly adjusted carburettor High speed jet HTensioning the recoil spring Air filterSpark plug Changing a broken recoil springMuffler Adjustment of the oil pumpWhen making adjustments Needle bearing lubricationElectrical carburettor heating CS 2147WH, CS 2152WH Centrifugal cleaning TurboHeated handles CS 2147W, CS 2152W Winter useMonthly maintenance Daily maintenanceWeekly maintenance Below you will find some general maintenance instructionsTechnical Data Technical dataBar and chain combinations EC-declaration of conformity Applies to Europe onlyCispr 121997, EN608 Page 1088890-26
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