Carburetor Adjustment Trimmer Echo 350 Es

Despite the high productivity, mobility and unpretentiousness in work, modern lawn mowers are difficult to attribute to complex devices. Over time, any mechanism undergoes wear, and therefore parts and assemblies require special attention of the owner. One of the elements of the trimmer is a carburetor, designed to form a fuel mixture and its supply to the combustion chamber. Increased consumption with the correct proportions of gasoline and oil or a drop in engine power indicate the need to adjust the carburetor of the gas trimmer.

Trimmer carb setting

The initial step in restoring the correct operation of the fuel system is to clean the air filter.

Carburetor Adjustment Trimmer Echo 350 Es

Screw trimmer carburetor

Experts recommend rinsing it in a solution of water with detergents after every 10-15 hours. Direct adjustment of the trimmer carburetor is carried out by three adjusting screws:

  • Fuel feed adjustment screw (“L”);
  • Adjustment screw at high speeds ("H");
  • The screw responsible for idling the motor (“T” or “AT”).

Adjustment of fuel supply at the minimum turns

Before starting the carburetor adjustment of the gas trimmer, it is necessary to warm the engine to operating temperature.

Fuel Adjustment Screws

To do this, start the engine and at idle let him work 10-15 minutes. At the first stage, with the trimmer working, slowly tighten the screw “L” until the beginning of intermittent operation or until it dies. Next, unscrew the screw by ¼ turn and check the speed of maximum speed. If the lawn mower easily and quickly reaches high speeds, this will be the most economical mode. In most models on the market, the fuel screw “L” is turned clockwise, however, there are trim tabs where the decrease and increase in the mixture flow occurs in the reverse order.

Trimmer idle adjustment

Location of carburetor adjustment screws

The screw "T" ("AT") serves as a limiter of the reciprocating movement of the fuel shutter and when it is twisted, the engine rpm increases, and turning it off leads to a decrease in the crankshaft speed. Professionals advise adjusting the idling screw of the lawn mowers so that the ICE works a little faster at minimum speed, but the head with the fishing line or knife remains motionless. If it is difficult to start the trimmer “cold” after the manipulations, then it is enough to tighten the “T” screw a quarter of a turn and try to start the engine again.

Adjustment of the screw of the maximum turns of a lawn-mowing

After restoring the fuel supply at minimum speed and adjusting the idle speed, it is necessary to check the stability of the mechanism at an increased speed.

Setting at maximum speed

Adjustment of the motor at high speeds is carried out in order to protect against overheating and reduce hand fatigue when pressing the accelerator key. If the internal combustion engine is unstable at maximum speed, then screw “H” must be slowly turned in to ensure smooth and clear operation.

During operation of the lawn mowers, it may be necessary to adjust the fuel feed screw (“L”) for an optimal set of revolutions.

Tips for repairing a gas trimmer carburetor

  1. Regardless of the manufacturer, there is a factory defect of the carburetor parts of the lawn mowers.

Adjusting screw spring

For example, the adjustment procedure described above may not give positive results with an excessively large number of turns at the spring of the mixture feed screw and, as a result, the impossibility of optimally reducing the level of gasoline supplied. To eliminate this, you can independently shorten the spring yourself or purchase a new one in accordance with the instruction manual.

Many owners of lawn mowers when buying oil follow the recommendations indicated there for the preparation of the fuel mixture.

Oil for gas trimmer

So, often the information on mixing gasoline and oil indicated on the bank differs from the instructions in the trimmer’s passport. As a result, a black deposit can quickly form on the spark plug, which leads to a drop in power and an increase in fuel consumption. Therefore, when preparing the working mixture, the recommendations specified in the instruction manual should be followed. In most cases, the proportion for a run-in ICE is 1:25. It is worth noting that many tool owners prefer to cook fuel “by eye”, which will inevitably lead to rapid wear of the piston spit in the event of a decrease in the portion of oil and the formation of soot on the spark plug with an increased amount of lubricating fluid.

Video: Carburetor Adjustment Trimmer Echo 350 Es


  • The correct tips for setting up the trimmer carburetor correctly performed above will help to avoid not only engine overheating and increased fuel consumption, but also significantly increase the life of other parts and components of the tool. Pay attention to the operation of the lawn mowers in all modes and timely carry out regulated maintenance and repair of the tool.
  • Husqvarna carburetor adjustment is done if:

    And, to be sure that the Husqvarna engine works as expected and that the maximum trimmer performance (lawn mowers, lawn mowers) is ensured.

    Husqvarna carburetor adjustment

    Before adjusting the Husqvarna, perform trimmer maintenance (wash the lawn mower and engine, replace the spark plug, and remove minor defects).

    Be sure to wash the foam element of the air filter. Wash the item in warm water with soap, then squeeze and dry (or replace if it is old or damaged).

    Note: If you adjust the Husqvarna carburetor with a dirty air filter, then after cleaning the air filter, the fuel mixture will become much poorer (which can lead to poor performance or even engine failure). Install a trimmer head with a cord of the maximum allowable diameter and standard length (up to the cutting knife in additional protection) to create a load on the engine while adjusting the Husqvarna carburetor high speed screw. Start the lawn mowing machine according to the Husqvarna Manual and warm it up for 10 minutes (if the trimmer head rotates at idle, the idle screw, i.E. The lower one, must be turned counterclockwise until the trimmer rotation stops). Carefully turn both needles (right and left) to the middle position between fully twisted and fully twisted (do not turn the stopper!, This may cause the Husqvarna engine to malfunction).

    The adjusting screws for adjusting the Husqvarna carburetor are three: right, left and bottom.

    1) Right screw L – regulates the enrichment of a mixture of low speed (regulated first):
    Find the maximum idle speed by slowly turning the right screw to the right and left.
    Then turn this screw ¼ turn counterclockwise.
    Note: From the Husqvarna factory, the right screw was completely unscrewed (0.5 turns). Now he is looking at 11 o’clock. 2) Bottom screw T – adjustment of the idle speed of the Husqvarna engine (if necessary): turning the screw clockwise increases the idle speed, counterclockwise decreases it.

    Correct is considered to be idle speed adjustment when:

    1. A cold engine idles steadily.
    2. A hot engine does not have too high idle speed.
    3. Before the start of rotation of the trimmer head, a sufficient margin of revolutions remains.
    4. The engine works stably in any position (for example, when the knife is sharply lowered).

    Note: From the factory (Husqvarna), the idle screw from fully tightened was unscrewed 8 full turns and “2 hours” (now it remains). The recommended idling speed of the Husqvarna lawn mowing engine is 2.900 rpm. 3) Left screw H – regulates the enrichment of a mixture of high speed (last adjusted).
    It regulates the maximum speed, engine power, temperature and fuel consumption.

    Note: The Husqvarna engine must not run at full speed for more than 10 seconds!

    • Open the throttle fully (full throttle) and slowly turn the left screw clockwise until the Husqvarna engine speed is reduced (by ear).
    • Then turn the left screw very slowly counterclockwise until the engine starts to run unevenly.
    • After that, turn the screw slowly back a short distance clockwise until the Husqvarna engine runs smoothly.

    This completes the Husqvarna adjustment.

    Note: Recommended maximum high engine speeds of Husqvarna – 11.500 rpm.
    The maximum power output of the Husqvarna 333R lawn mowing engine is 1.6 kW (2.1 hp) at 8,400 rpm.

    Note: On the new Husqvarna trimmer from the factory (Husqvarna), the left screw was completely unscrewed (0.5 turns) and locked (filled) with hard plastic, which I drilled after the warranty period. Now the left screw (as well as the right one) looks at approximately 11 o’clock.

    Checking the correct setting of the Husqvarna carburetor

    The engine quickly, smoothly and confidently picks up speed, and quadruples a little at maximum speed, the T-35 trimmer head should not rotate at idle.

    Reference. Read to understand what you are doing!

    The required composition (quality) of the air-fuel mixture is adjusted (changed) by turning the screws to adjust the fuel supply to the intake air flow (right and left). The amount of mixture entering the cylinder is dosed by the throttle.
    If you turn them clockwise, the mixture that is sucked into the cylinder is leaner (less fuel in the air / fuel ratio) and the engine rpm increases, while the Husqvarna engine runs softer (weakly gaining speed) and the power drops drastically. In addition, having increased revolutions, less oil (worse lubrication) enters the cylinder on the lean mixture with gasoline (worse lubrication), and so the engine can be shut off. Well, the trimmer will not start well.
    If you turn the screws counterclockwise, the mixture that is sucked into the cylinder enriches (more fuel in the air / fuel ratio) and the engine rpm decreases, while at low rpm more gasoline and oil get into the cylinder (better traction, better lubrication), but the Husqvarna engine "Unwinds" poorly (poorly gaining momentum) and more carbon deposits form in the cylinder!

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