Adjusting the carburetor on the Husqvarna 125r brushcutter

Frequent malfunctions of the Husqvarna 128R grass trimmer

The number of problems that can be solved by adjusting the carburetor is rather large. Adjusting the carburetor of a Husqvarna chainsaw is necessary when there are such malfunctions as:

  • high idle speed;
  • strong smoke when the tool is working;
  • Difficulty starting a cold or hot engine;
  • lack of traction and reduced maximum rpm.

This is by no means a complete list of problems that can be solved by adjusting the Husqvarna carburetor. In some cases, adjustment of the quality and quantity of the fuel mixture is carried out after the overhaul of the engine or during the scheduled maintenance of the chainsaw.

The manufacturer of the Husqvarna AB recommends adjusting the carburetor before and after running-in.

Get the carburetor to adjust

Module configuration is not repairable, and replacement is not required. Honda Carburetor Cleaning the carburetor. In this case, a carburetor repair kit for a gas grass trimmer is not required.

  • L. is initially adjustable because it is responsible for fuel delivery at low speeds;
  • N. Is responsible for gasoline delivery at high speeds, as well as fuel consumption and temperature;
  • T. it can be used for easy adjustment.
adjusting, carburetor, husqvarna, 125r

There are variants, as a rule, the carburetor of the Chinese gasoline scraper, when there is only one screw on the body for adjustment. To adjust the idle speed. This does not mean that the module adjusts automatically. This means that it will be difficult to perform even this type of repair as a debugging. The photo shows the adjustment of the Chinese gasoline carburetor.

  • The module is adjusted only when the engine is warmed up: to do this, first turn it on for 10 minutes. Adjusting the carburettor If the mower head is idling, start the adjustment immediately: turn the screw T counterclockwise until it stops turning.
  • Adjustment begins with the L screw. The screw rotates to the left and right until it finds its position where the idle speed is at its maximum.
  • Then turn the screw and turn it counterclockwise. This will be its working position.
  • Idle action should be adjusted by turning counterclockwise to increase speed, and clockwise. reduce. Its adjustment consists in reaching the mode, in which the sufficient rotation is performed before the mower starts to rotate. In this case, the engine should run steadily in different positions.
  • The position of the L screw is determined by the last. at maximum speeds, the grass trimmer should not run for more than 10 seconds. The choke is opened, the screw is turned clockwise, very slowly, until the rate of rotation is reduced to ear level.
  • Then the screw also rotates slowly counterclockwise until the engine starts to run with a glitch. Then the screw is turned back clockwise until the engine restarts normally.

We suggest reading Shoes for Extremely Low Temperatures If you have a tonometer and if the product data sheet specifies the recommended speed, the correction can be made more accurate by focusing on the readings of the device rather than on the ear.

Please explain. In the adjustment section of item 5, the L L screw? Should I read the screw A? Thanks

tell me the initial position of the screws H L LA

Tell me the initial position of the screws H L LA

Major carburetor problems and malfunctions.

Grid There are only two tasks with this item:

To determine the cause of the failure, remove the fuel filter cap to repair the leak. If it’s just dirty, flushing with gas or purging would help.

For visible damage, the strainer should always be reinstalled. There may also be damage to the fuel line (check this element for repair).

The carburetor starter almost always fails because of a blockage. Use acetone or the same gasoline to wash.

Blowing out carburetor components with compressed air is an acceptable and convenient repair practice.

Throttle body, carburetor component bundles, intake or exhaust pipe. all of these parts are airtight. You can probably check in a simple way. Caulk the problem area with soap deposits.

How it works gasoline carburetor braids

The throttle valve determines the amount of air flow and the engine output is directly dependent on it.

Fuel is sucked into the carburetor system by the pump (its diaphragm). It then passes through a fitting in the carburetor. The fluid then moves through the inlet and outlet valves of the pump. Filtered by mesh. The needle valve moves into the diaphragm chamber.

  • The air supply to the pipe is made through an air baffle (damper). A baffle plate controls the intensity of the air flow.
  • The fuel system must be narrowed by a diffuser to increase flow.
  • Gasoline through the float chamber and tapered nozzle tube. The float chamber regulates the temporary volume of gasoline. In the float chamber, the pressure level is neutral, and in the tube with a constriction, it is already low. Because of the pressure drop, the fuel enters the nozzle.
  • Acceleration of air flow facilitates fuel (gasoline) transfer and atomization. The result is an air-fuel mixture of the desired proportion or density.
  • The air-fuel mixture enters the engine cylinder through the fuel tube.

The level of air density in the system depends on the area of the open air flap. The wider the valve is open, the better the fuel flow and performance.

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Simply put, adjusting the carburetor on the brush creates an optimal fuel-air mixture due to the proper air supply.

Husqvarna 125R carburetor adjustment without a tachometer (temporary solution)

How do I adjust the carburetor if I have to work and the service is far away with a tachometer?

In the carburetor system, the fuel is sucked in by the pump (its diaphragm). Then goes through the choke in the carburetor. The fluid then moves through the inlet and outlet valves of the pump. Filtered grid. The valve needle moves into the diaphragm chamber.

  • Air supply tube with air baffle (valve). Baffle plate controls the intensity of the air flow.
  • The system is tapered by a diffuser to increase the flow rate.
  • Gasoline through the float chamber and reactive tube with constriction. A chamber with a float regulates the temporary volume of petrol. In the float chamber, the pressure level is neutral, but in the tube with constriction, the pressure level is already low. Differential pressure causes fuel to pass through the jet.
  • Acceleration of air flow facilitates fuel (gasoline) transfer and atomization. The result is an air-fuel mixture of the desired proportion or density.
  • enters the engine cylinder through the fuel pipe.

The level of air density in the system depends on the area of the open air damper. The wider the baffle plate, the greater the flow rate and output.

Simply put, carburetor adjustment at the gasoline pump. Creating an optimal fuel mixture due to proper air supply.

General Info

Husqvarna is a company from Sweden, which is a world leader in the production of various garden tools. Husqvarna products are trusted by customers around the world.

One of our most popular grass trimmer models is the Husqvarna 128r.

This is a lightweight lawn mower, which is designed to keep small household plots clean.

The low weight is one of the main design features of the Husqvarna lawn mower. The grass trimmer weighs only 5 kg.

This point is very important for future owners, because the lawnmower is carried on the shoulders, and over time, fatigue sets in.

Synopsis. Read on so you know what you’re doing!

The desired composition (quality) of the fuel-air mixture is adjusted (changed) by turning the fuel adjustment screws in the intake air flow (right and left). The amount of mixture entering the cylinder is metered by the throttle valve. If it is turned clockwise, the mixture inside the cylinder is leaner (less fuel in the air/fuel ratio) and the engine rpm increases, with the Husqvarna engine running softer (it has lower rpm) and power drops dramatically. Besides, with higher revolutions, less oil (worse lubrication) gets into a cylinder with lean mixture and so it is possible to screw up the engine. Well, and grass trimmer will not start well. If you turn the screws counterclockwise, the mixture sucked into the cylinder is enriched (more fuel in the air/fuel ratio) and the engine speed decreases, while at lower rpm more gasoline and oil get into the cylinder (better traction, better lubrication), but the Husqvarna engine “untwists” badly (does not gain speed) and more soot is formed in the cylinder!

This is interesting: carburetor cleaner

adjusting, carburetor, husqvarna, 125r

Principle of operation

A carburetor is a power source in which liquid fuel and air mix before entering the engine cylinders. Depending on the tool and its mode of operation, mixing and feeding are adjusted accordingly.

The design of the carburetor is the same in almost all cases. Refers to the category of floating devices. The latter provide stable parameters of ready mixtures.

The principle of operation of the module is as follows.

  • Air flows into the tube housing with an air damper. The latter increases or decreases the air flow depending on its position.
  • In the area where the opening for gasoline is formed, the tube has a narrowing. Diffuser. Here the flow rate increases.
  • Fuel from the float chamber is discharged into the pipe through a nozzle. The level of the float determines the quantity of fuel. As the pressure in the chamber is normal and low in the pipe due to the greater air rarefaction, gasoline is sucked in through the nozzle.
  • Accelerated airflow collects fuel and atomizes it, forming a fuel-air mixture of desired density.
  • The mixture is sucked into the cylinder through a tube.

The more open the air valves in the tube, the higher the airflow density, which means more fuel goes into the cylinder. Setting a brush carburetor comes down to setting the ratio of dampers so that the density of the fuel mixture becomes optimal.

Adjusting the Husqvarna 128r Carburetor Gas Cutters

The result of adjusting the gasoline carburetor braids.

Grass trimmer is not a complex household appliance, so most of its failures are mechanical in nature and can be successfully repaired with their own hands. Cleaning the carburetor of lawn mower Honda izy. Even if the engine fails for serious reasons. For example, damage to a piston ring, repair comes down to replacement.

But even with a relatively simple design, a part of the device, such as the carburetor, you need to adjust.

Operating principle

The carburetor is a power source in which liquid fuel and air are mixed before being fed into the engine cylinders. Depending on the tool and its mode of operation, mixing and feeding are adjusted accordingly.

The design of the carburetor is the same in almost all cases. Refers to the category of floating devices. The latter ensure stable parameters of ready mixtures.

The principle of operation is as follows.

  • The air enters the tube body with an air damper. The latter increases or decreases the air flow depending on its position.
  • In the area where the gasoline orifice is formed, the tube has a constriction. Diffuser. Here the flow speed increases.
  • The fuel from the float chamber is fed into the pipe through a nozzle. The carburettor device for lawnmowers. Carburetor settings The float level determines how much fuel is delivered. Since the pressure in the chamber is normal and low in the tube due to greater air rarefaction, gasoline is drawn in through the nozzle.
  • Accelerated airflow gathers the fuel and atomizes it, forming an air-fuel mixture of desired density.
  • The mixture is sucked into the cylinder through a tube.
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The more open the air valves in the tube, the higher the density of the air flow, which means that more fuel enters the cylinder. Installing a brush carburetor comes down to setting the ratio of dampers at which the density of the fuel mixture becomes optimal.

Adjusting the carburetor on a Husqvarna 125, 128 brushcutter

Husqvarna carburetor operations involve a nozzle valve that atomizes the fuel and prevents air from entering the main chamber. It is not uncommon for problems during the operation of the saw to be caused by shortcomings of this particular element. For example, the valve, in case of wrong storage of a chainsaw can jam, the fuel supply will run out, making the work of the motor impossible. Also, violations in the operation of the nozzle will be a prerequisite for air suction into the main fuel chamber of the carburetor. In this variant, the adjustment of the adjusting screws will not correct the situation and repair or change of the unit is useful.

Three adjustment screws installed in the carburetor body are responsible for adjusting the consistency properties and quantity, and similarly the number of crankshaft revolutions in idle mode:

  • screw (L). adjusts the amount of fuel operating at low and medium rpm;
  • (H). responsible for traction at high RPM and their number;
  • (T). changes position of throttle slide, thus regulates amount of fuel consistency entering a cylinder and engine operation in idle mode.

Screws (L) and (H) can not be adjusted without certain knowledge and experience. Improper adjustment of the properties and amounts of fuel consistency leads to the fact that the engine will not work as it is still called works incorrectly, leading to its sharp wear or even jamming.

An ordinary slotted screwdriver is not suitable for adjusting, because. к. the adjusting screws on the Husqvarna chain saws have different sections. You have to buy a special, this particular feature of Husqvarna chain saw repair, they have created our customer remains, that the saw can be repaired only in special Husqvarna service.

Husqvarna carburetors (factory settings)

Husqvarna carburetor is adjusted in the same way as carburetors on chain saws from other manufacturers are adjusted.

Before making the adjustments you have to perform a thorough diagnostics to make sure that there is no fuel blockage or air bleed in the chainsaw’s crankcase. You should also make sure the air filter is clean and replace it with a new one if you wish.

  • Husqvarna carburetor options are installed on the chainsaw when not in use.
  • Starts the engine and warms up the saw in a few minutes.
  • By turning the screw (L) clockwise, is the position when the engine develops the greatest speed, then the screw should be turned back to 1⁄4. If in all this chain saw chain spins, you need to reduce the idle speed, by adjusting the position of the screw (T).
  • The next step is to adjust the power of Husqvarna at the highest rpm and adjust the number of rpm. For this purpose, connect the tachometer to a running chainsaw, press the throttle grip all the way down and check the tachometer reading. If the maximum rpm differs from the maximum recommended by the Manufacturer, then the tachometer reading is reset by adjusting the propeller position (H).

After the adjustment, the chainsaw should simply start and stop, and run smoothly at low and high RPMs. If the saw chain spins at idle after adjusting the carburetor control screws, it is a sign that the adjustment was not done correctly and the screw position (T) needs to be corrected.

Also, when adjusting the Husqvarna carburetor it is worth considering the chain saw’s response time to turn the screws. Options do not change immediately, within 5, 10 seconds.

How to adjust the carburetor on a chain saw

Before adjusting, it is necessary to thoroughly clean the filters according to the maintenance in the manual.

Further adjustment of the lawnmower carburetor with your own hands is made with the adjusting screws. There are three in total:

It is necessary to find the maximum revolutions at idle. To adjust the idle speed, turn the screw (L) slowly to the right and left.

Always turn the screw a quarter of a turn counterclockwise for adjustment.

It is characteristic for the correct idle speed adjustment:

  • stable operation of the cold engine
  • hot engine revolutions are not excessive;
  • For the trimmer head, a large RPM margin;
  • stable operation of the engine when changing the position (sudden raising or lowering of the blade).

The left screw (H) determines the overall adjustment of maximum rpm, engine power, temperature, and gasoline consumption.

Adjusting the lawnmower carburetor with the last screw is done as follows:

  • Open the throttle all the way, with full throttle. Turn the screw clockwise until the rpm drops (in this case, orienting by ear).
  • Turn it as slowly as possible counterclockwise until the engine runs rough.
  • Then turn back just a little, barely hearing a steady, even operation.
  • For a more obvious application of skills, it’s more convenient to review the work of an experienced user:

the correct adjustment of the carburetor with your own hands in this case. combustion of the fuel mixture without residue, the color of the candle should be light brown.

Adjusting the brushcutter carburetor in practice. video

Adjustment of the Husqvarna grass trimmer carburetor is identical to the carburetor adjustment of a Husqvarna chainsaw.

Fixing a Husqvarna 128R lawn mower

I decided to write a couple of lines about the Husqvarna 128R mower. I bought this tool 2 years ago. I think it is a great tool, I will mow and mow. Didn’t have much of a load 18 acres plus around the property.

adjusting, carburetor, husqvarna, 125r

Worked with it in a mode: spent a tank. let cool down for 20 minutes. Three in the summer.Four full runs around the property and the neighborhood. Poured Husqvarna oil. Couldn’t be happier because it would start with a bang. This year it stopped pulling and started badly. I even stopped using it much, because I assumed that nothing lasts forever and. maybe it got tired of me. Maybe try to do it myself, I thought and went to get the tools. I’ll start by cleaning the carburetor. I assumed, and, without thinking too much, went into the bowels of the lawnmower.

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The first thing I did was to take off the spark plug and clean it, it would be better to replace it, but I didn’t have. No result, it just shuts off at idle. I took the spark plug off and checked the spark. The spark is still there. then no. Started probing and experimenting. It turned out that the lug of the high-voltage wire had just fallen off. I think I do not want to look for a new wire, time and money must be saved. Soldered the core of the high-voltage wire to the lug, reassembled, waiting for the victory. but it’s still there. It is possible that the spark was in the damaged spark plug wire and it did not affect the spark plug performance. I take it apart again to remove and clean the lawnmower carburetor, and it’s just dangling. From the vibration just unscrewed. It turns out that when revving the engine, air flew into the gap, impoverished the already poor gasoline mixture and gasped, and at idle was struggling somehow. So, here is American quality assembled in China. These are the sprocket bolts.

adjusting, carburetor, husqvarna, 125r

You will need a screwdriver for the replacement lugs, a sprocket lug and a hex. It’s a pain in the ass to take apart. But that’s probably the key to reliability. Carefully and slowly you will get it all.

Air filter chamber. Cleaned filter in kerosene. Good as new. After that it needs to be “moistened” in any oil. I will not describe the grass mower assembly. The main thing is not to lose the bolts and not to mix them up. Different bolts with fine and coarse threads. Large into the plastic. Shallow on the metal. The entire repair took about 2 hours. Good luck!

The spring could get in the way

My first attempt to adjust the carburetor lawnmower gave nothing, because prevented the spring of the screw to adjust the fuel mixture. The factory spring turned out to be too thick in a compressed state and did not allow to reduce the fuel feed to the required level. Had to pick up another spring and continue adjusting after replacing it.

Fuel mixture adjustment screw with spring

Pictured above is the factory spring, below is the adjusting screw with a matching spring. I’m writing about this because I’m not sure if this is an isolated incident and someone else might encounter the same situation.

From personal experience

lawn mower or grass trimmer

grass trimmer is a broader concept than a lawnmower (lawn mower), as it can also be electric. Gasoline grass trimmer and lawnmower. they are one and the same.

Some authors assure that the grass trimmer. it is a weaker tool, unlike the more powerful lawnmower, which can be used to mow bushes. Personally, I have a tool with a maximum power of 1.7 kW and capable, as stated in the manual, to mow small shrubs up to 10 mm thick. The owner’s manual is called a gasoline lawn trimmer. “.

Proportion of fuel mixture

I read somewhere that if the manual of the lawnmower and the oil can indicate different proportions of fuel mixture preparation, you should use the proportion indicated in the manual.

For a long time that’s how I did it. Too much oil used to leak out of the engine onto the fuel tank and the spark plug always had a soot on it, because the manual showed the ratio for a running-in engine as 1:25, but the canister. 1:50. After switching to 1:50 the oil drips stopped. The spark plug continued to burn, but with less intensity (the carburetor was not yet adjusted).

To this day, some users of gasoline tools determine the proportion of the fuel mixture “by eye. If during the preparation of the mixture will be reduced amount of oil, after a while there may be a strange sound immediately after starting the engine, gradually disappearing during the warm-up, and the engine stops with a sharp jerk. Continued operation of the grass trimmer in this mode will lead to its failure.

Plug cleaning

In the worst times of running a trimmer with an unadjusted carburetor, the engine would stop starting after using every tank of fuel. And only after the plug was cleaned from soot, could the work be continued.

Fine sandpaper was used to clean the electrodes, and to clean the space between the insulator and the body. a thin paper clip with a bent end. First, the electrodes were wiped of a lot of dirt with a rag, and then sanded with sandpaper. The spark plug was then immersed in diesel fuel and the soaked soot scraped off with a paper clip from the surfaces of the insulator, the inside of the housing and between the insulators. Then the plug was immersed several times in diesel fuel, which was then shaken off with its impurities. Sometimes the cleaning procedure with a paper clip and rinsing was repeated. After that the candle was wiped dry and was ready for further use.

Unbelievable, but one canister of fuel mixture with an unregulated carburetor can be used up in less than 10 minutes. checked in practice when the grass trimmer was started and operated at high revolutions with maximum fuel delivery (the adjustment screw was unscrewed much more than normal).