Husqvarna Essential Carburetor and Idle Adjustment Tips for 455 Rancher Chainsaw
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MAINTENANCE

General

The user must only carry out the maintenance and service work described in this Operator’s Manual. More extensive work must be carried out by an authorised service workshop.

Carburettor adjustment

Due to existing environmental and emissions legislation your chain saw is equipped with movement limiters on the carburettor adjuster screws. These limit the adjustment possibilities to a maximum of a 1/2 turn.

1/2

1/2

Your Husqvarna product has been designed and manufactured to specifications that reduce harmful emissions.

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

L

H

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.

Basic settings and running in

The basic carburettor settings are adjusted during testing at the factory. Avoid running at a too high speed during the first 10 hours.

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

Rec. idle speed: 2700 rpm

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.

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, maximum 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.

•Do not attempt to adjust the L and H jets beyond either stop as this could cause damage.

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

•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

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.

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.

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Contents Rancher Symbols in the operator’s manual KEY to SymbolsSymbols on the machine Contents Dear Customer Introduction20 19 What is what on the chain saw? What is WHAT?Always use common sense General Safety PrecautionsBefore using a new chain saw Chain brake and front hand guard Machine′s safety equipmentPersonal protective equipment General Safety Precautions Chain catcher Throttle lockRight hand guard Vibration damping systemCutting equipment Stop switchMuffler General rulesBar Cutting equipment designed to reduce kickbackChain Some terms that describe the bar and chainGeneral advice on adjusting depth gauge setting Sharpening your chain and adjusting depth gauge settingGeneral information on sharpening cutting teeth Sharpening cutting teethTensioning the chain Adjustment of depth gauge settingLubricating cutting equipment Chain oilChain drive sprocket Checking chain lubricationNeedle bearing lubrication Checking wear on cutting equipmentBar Fitting the bar and chain AssemblyFitting a spike bumper Working with the chainFuel Fuel HandlingFuelling Fuel safetyTransport and storage Long-term storageStarting and stopping Starting and StoppingCold engine Warm engineStopping Working Techniques Basic safety rulesBefore use General working instructionsAlways use a fast cutting speed, i.e. full throttle Terms Basic cutting techniqueGeneral Log is supported at one end. There is a high risk that it LimbingCutting Safe distance Tree felling techniqueFelling direction Clearing the trunk and preparing your retreatFelling cut FellingDirectional cuts Freeing a tree that has fallen badly General adviceFreeing a trapped tree Cutting trees and branches that are in tensionCutting the trunk into logs How to avoid kickbackWhat is kickback? General MaintenanceCarburettor adjustment High speed jet H Correctly adjusted carburettorThrottle lock Changing a broken or worn starter cord MufflerStarter Spark plug Air filterTensioning the recoil spring Changing a broken recoil springWhen making adjustments Adjustment of the oil pumpLubricating the bar tip sprocket Needle bearing lubricationTemperature 0C or colder Air Injection centrifugal cleaningTemperature -5C or colder Winter useDaily maintenance Weekly maintenance Monthly maintenance Maintenance scheduleTechnical data Technical DataBar and chain combinations ´z+H8h¶6S¨ 38 English´z+H8h¶6S¨EN ISO 12100-22003, Cispr 122001, EN ISO EC-declaration of conformityApplies to Europe only 1140247-26 ´z+H8h¶6S¨ ´z+H8h¶6S¨
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455 RANCHER specifications

The Husqvarna 455 Rancher is a powerful chainsaw designed for both professional users and avid homeowners. Renowned for its robust construction and unparalleled performance, this chainsaw is an excellent choice for those who demand reliability and accuracy in their outdoor tasks.

At the heart of the 455 Rancher is its 55.5 cc X-Torq engine, which offers a perfect blend of power and fuel efficiency. This advanced engine technology reduces fuel consumption by up to 20% while simultaneously minimizing exhaust emissions, making it an environmentally conscious choice. The system also provides higher torque over a wider RPM range, ensuring that users have the power they need when cutting through larger logs or tough wood.

The 455 Rancher features a high output air filtration system, which enhances the lifespan of the chainsaw by ensuring the engine stays clean and well-protected from dust and debris. This system is particularly beneficial for users who work in dusty or challenging environments, as it requires less frequent filter cleaning and replacement.

Another notable characteristic of the Husqvarna 455 Rancher is its anti-vibration technology. This feature minimizes vibrations during operation, significantly reducing operator fatigue and enabling longer and more comfortable use. The chainsaw also comes equipped with an ergonomic design, including a well-balanced construction that allows for better maneuverability.

Safety is paramount with the 455 Rancher, which is equipped with a variety of safety features. The chain brake is a critical component that helps prevent accidental injury by halting the chain's movement in the event of kickback. Additionally, the chainsaw includes a low kickback chain designed to lessen the risk of kickback incidents while cutting.

The chainsaw boasts an adjustable oil pump that allows users to control the amount of oil delivered to the chain, ensuring optimal lubrication and extending the life of the chain and bar. Combined with an easy-to-access fuel and oil tank, the Husqvarna 455 Rancher is engineered for user convenience.

In conclusion, the Husqvarna 455 Rancher stands out for its powerful engine, efficient fuel consumption, advanced safety features, and user-centric design. Whether for professional forestry work or home landscaping projects, this versatile and durable chainsaw is a reliable tool that can tackle a wide range of cutting tasks with ease.
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