Factory Settings Carburetor Husqvarna 240. Carburetor Husqvarna lawn mower

Factory Settings Carburetor Husqvarna 240

Modern chainsaws have a complex system and consist of several main components, which periodically require maintenance and adjustment. In this article, we’ll talk about how to adjust the carburetor on a Husqvarna chainsaw.

When does the Husqvarna chainsaw carburetor require adjustment

There are many problems that can be solved by adjusting the carburetor. Husqvarna chainsaw carburetor adjustment is necessary when a malfunction occurs such as:

• increased idle;
• heavy smoke during tool operation;
• difficulty starting a cold or hot engine;
• lack of traction and lower maximum revs.

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

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

The device and principle of operation of the Husqvarna carburetor

To successfully set up a Husqvarna chainsaw carburetor, you need to know its device and understand how it works. In fact, everything is not as complicated as it seems at first glance.

The saw carburetor has a built-in fuel pump, which is responsible for transporting a mixture of gasoline with oil, as well as a diaphragm, a needle valve with a rocker. Their joint work allows metering the fuel supply to the main chamber and two shutters.

One of the dampers is designed to adjust the fuel supply to the cylinder when pressing the gas, it is called the throttle, the second is responsible for restricting the air supply from the air filter to facilitate the start of the Husqvarna cold chainsaw. At that moment, when the operator shuts off the air supply to the carburetor with the help of an air damper, the fuel mixture is depleted and its supply to the cylinder is increased, due to which the chainsaw starts up much easier than when the cold start is carried out in normal mode.

An injector valve is involved in the operation of the Husqvarna carburetor, which atomizes the fuel and prevents air from entering the main chamber. Often problems when working with a saw can be caused by defects in this particular element. For example, a valve, if the chainsaw is not stored properly, can stick, fuel supply will stop, which will make the engine impossible. Also, malfunctions of the nozzle can cause air to leak into the main fuel chamber of the carburetor. In such cases, adjusting the position of the adjusting screws will not correct the situation; repairs or replacement of the assembly will be required.

For adjusting the quality and quantity of the mixture, as well as the number of revolutions of the crankshaft in idle mode, there are three adjusting screws installed in the carburetor body:

• screw (L). adjusts the amount of fuel in low and medium speed mode;
• (H). responsible for traction at high speeds and their number;
• (T). changes the position of the throttle valve, thereby regulating the amount of fuel mixture entering the cylinder and the engine’s engine idling.

Screws (L) and (H) cannot be adjusted without specific knowledge and experience. Incorrect adjustment of the quality and quantity of the fuel mixture can cause the engine to stop working or malfunction, which will lead to its Rapid deterioration or even jamming.

Video: Factory Settings Carburetor Husqvarna 240

Tools necessary for work

Before setting up the Husqvarna carburetor, you need to take care of the availability of all the tools that may come in handy. To carry out this type of work yourself, you will need:

An ordinary slotted screwdriver is not suitable for adjustment, because the adjustment screws on Husqvarna chainsaws can have a different cross-section. You have to purchase a special one, this is the peculiarity of repairing Husqvarna chainsaws, they did everything so that the saw could be repaired only in a specialized Husqvarna service.

Husqvarna carburetor algorithm and description

Husqvarna carburetor, is regulated similarly to how carburetors are adjusted on chainsaws from other manufacturers.

Immediately before the adjustment, it is necessary to conduct a complete diagnosis of the saw and make sure that there is no difficulty in supplying fuel and air intake into the crankcase of the chainsaw. You must also make sure the air filter is clean and replace it with a new one if necessary.

The procedure for the work is as follows:

• Husqvarna carburettor factory settings are set on the muffled saw.
• The engine starts and the saw warms up for several minutes.
• By turning the screw (L) clockwise, there is a position at which the engine develops maximum speed, after which the screw must be turned back 1⁄4. If at the same time the chain of the chainsaw rotates, then it is necessary to reduce the idle speed by adjusting the position of the screw (T).
• The next stage is the adjustment of the power of Husqvarna at maximum speed and the adjustment of their number. To do this, the tachometer is connected to the wound chainsaw, the throttle stick is squeezed to full, after which the tachometer readings are checked. If the maximum speed value differs from the maximum quantity recommended by the manufacturer, then by changing the position of the screw (H), the tachometer readings are normalized.

Adjustment nuances

After adjustment, the chainsaw should easily gain and lose speed, work stably at low and high speeds. If the saw chain rotates at idle after adjusting the carburetor control screws, this is a sign that the setting is incorrect and that the position of the screw (T) needs to be adjusted.

Also, when adjusting the Husqvarna carburetor, it is worth considering the response time of the chainsaw to the rotation of the screws. Settings do not change immediately, but within five, ten seconds.

One of the indicators of incorrect adjustment is a strong smoke during the operation of the saw, which indicates a large amount of fuel entering the combustion chamber. If this situation arises, adjust the position of the screw (L).

Factory settings

The factory default settings for the Husqvarna carburetor are the position of the screws (H) and (L), in which a working chainsaw must be guaranteed to start. For Husqvarna tools, this is one and a half turns from fully tightened screws (H) and (L). In the process of adjustment, you must first set the screws in the standard position, then start the chainsaw and make an accurate adjustment of power, the number of maximum revolutions and idle revolutions.

DIY carburetor repair

If during the complete diagnosis of the Husqvarna chainsaw, carburetor defects were detected, some of them can be eliminated without contacting the Husqvarna AB service center. For example, you can independently:

• change gaskets under the covers of the main chamber and fuel pump;
• clean or replace the strainer;
• replace the diaphragm or needle valve of the main chamber;
• repair the diaphragm of the fuel pump.

Gaskets, diaphragms and a needle valve with a rocker arm can be found in the repair kit that is available for each model of Husqvarna chainsaw carburetors.

Also, if you have some experience, you can try to restore the faulty valve-nozzle, but you cannot guarantee a positive result when trying to restore the nozzle, if it is faulty, manufacturers recommend changing the carburetor completely.

The first thing to do before removing the carburetor from Husqvarna is to clean the saw with a compressor, since dirt can interfere with a quality repair. Next, you need to open the top cover of the chainsaw, remove the air filter, disconnect the rods from the control levers of the air and throttle valves. After that, unscrew the screws securing the carburetor.

Dismantling the carburetor body for repairs is quite simple. The cover of the main chamber is held by four screws, which can be removed using a conventional screw, the cover of the fuel pump is fixed with one wide screw.

Below is a video, watching which it becomes clear how it is possible to repair a carburetor without contacting a Husqvarna service center.

Conclusion

Work on setting up or repairing a carburetor on Husqvarna chainsaws can be completed without any specific experience. In order to do everything right, you must follow the algorithm and have a minimal set of tools. It is also worthwhile to evaluate your strengths in advance and not risk it if you do not understand anything at all in the technique. Believe me, sometimes it’s better to pay a small amount to the master than to spoil the instrument by self-regulation.

Husqvarna 240 Chain Saw. Carb Rebuild and Dissassembly

Learn the reasons why a lawn mower won’t start after winter or during peak season, and how to fix those problems.

Family Handyman

Introduction

Most of the time when a lawn mower won’t start the cause is a problem with the gas or the lawn mower carburetor.

What to Do if Your Lawn Mower Won’t Start

Whatever kind of lawn mower you’ve got, the last thing you want once winter finally lifts and spring has sprung is a lawn mower that won’t start.

If you’ve taken the proper steps to winterize your lawn mower, you’re far less likely to be dealing with such issues. It’s also why you should tune up your lawn mower at the start of every season. However, it’s not out of the ordinary to find your gas-powered lawn mower not starting from time to time, so it’s important to know why your lawn mower isn’t starting and how to fix it.

Project step-by-step (6)

Check the Gas Tank

Let’s start with the obvious. Before you have a heart attack pulling on the rip cord, you’ll want to check the fuel. Like any gasoline-powered engine, lawn mowers run out from time to time. Maybe you forgot it was running on fumes when you finished mowing last time. It sounds simple, but we’ve all overlooked the gas tank from time to time.

Even if there is gas in the mower, if the fuel’s been in there more than a month, that could be the problem. Gas sitting around too long in the tank can get contaminated with dirt and extra moisture.

So if your gasoline has been in the mower for more than month, drain the gas properly, dispose of it correctly, and fill up the mower with new gas. It may take quite a few pulls to suck the new gas into the lawn mower carburetor, so be prepared to clean and dry the plug a few more times.

Add fuel stabilizer when you fill up the tank to help protect the gasoline in there from dirt and moisture.

Family Handyman

Check the Spark Plug

Start by making sure the lawn mower spark plug cable is connected to the plug itself. It’s quite possible that it got pulled off there over the winter while the mower was being stored in the garage.

If that’s not the issue, the next step is to remove the spark plug to see if it’s wet. There’s no way the engine will start if it is. So clean the plug with carburetor cleaner and let it dry. Cleaning it with compressed air isn’t enough; you need a solvent to remove oil residue. If it’s really grimy and dirty, it might be best to change the spark plug.

Fertnig/Getty Images

How To Clean A Carburetor On A Lawn Mower Without Removing It

Machines have a lot of fast-moving parts that work together for the machine to function.

Just like a car, a lawnmower has a machine called carburetor that is responsible for the movement of the blade that cuts the grass.

A carburetor is a device that injects air into the fuel to have internal combustion. The combustion is what will power the blades.

Carburetors are present in large machines like commercial planes and to small ones like your trusty lawnmower.

Today, we discuss how to clean the carburetor in your lawnmower without removing it. This can be a good option if you do not have the technical knowledge and the right tools to do a thorough cleaning which requires removing the carburetor from the machine.

After all, sometimes all it needs is just a bit of cleaning.

Types of lawnmowers

These are the usual types of lawnmowers you can see at your local hardware depot.

• Traditionalpush-reel lawnmower. This one does not use an engine but rather relies on the kinetic energy provided by the turning wheels. A set of 5 to 8 blades work together to provide a basic cut. Do not expect fast or precision cutting with this one.
• Walk behind lawnmower. This one is the most popular due to its efficiency. You just push the lawnmower towards the uncut grass and everything is cut nicely and evenly after. The blades are located at the bottom which is powered by a small carburetor.
• Ride-on lawmowers. This one is operated similar to a car or a golfcart. Instead of pushing it, you sit on the machine and steer it. Usually, this machine is used on stadiums and large greenfield which requires faster cutting without tiring the person.

Common issues and symptoms of a faulty carburetor

The issue with any gas-power machine is you should regularly use it but not overuse it. Leaving it unused for a long time can lead to complications.

Liquids inside may harden and cause blockage in some parts. The grease may get gunky and cause the moving parts to be stuck.

You will easily know when the carburetor is acting up when it shows the following signs:

• Weaker engine and performance. If you notice that your lawnmower cannot any more cut evenly or have a hard time cutting denser grasses, the carburetor is definitely in bad shape, and attend to it immediately.
• Emission of black smoke. This means that the carburetor is consuming unusually high amounts of fuel. You will end up spending more on gasoline. Also, exposure to black smoke could lead to respiratory and dermatological problems.
• Overheating. Usually, this means that there is a poor mix or ratio of air and fuel. The engine exerts more effort to work.
• Suddenly shutting down. Simply put, any lawnmower should have no problem being used for an hour or two. When it suddenly shutdowns, it is an obvious sign that your carburetor needs some cleaning or fixing.
• Jumpy starting. Whether it is started via a push-button or pulling a cord, a lawnmower that has a hard time starting means that the internal parts are not at their optimum status.

Now you know how to spot a faulty carburetor. Let us now talk about whether you should remove it from the lawmower or not.

Why you should not (yet) remove the carburetor when you clean it?

Before you do anything, you should assess your technical know-how with small machines. If you are a mechanic who deals with this problem regularly, then removing the carburetor and putting it back would be easy.

Husqvarna 240.И снова о карбюраторе.Конструкторский ляп или что это?

If you are just a casual homeowner, better keep it intact and clean it from there.

You may successfully remove it and clean it, but you may end up having a hard time returning it. What is a clean carburetor if you cannot use it anymore.

Essential tools you need

Before you start cleaning, take a look of everything to assess how you will proceed with the cleaning. If you see exposed wires, a rat may have chewed on it.

If you see patches of rust, the carburetor may have been exposed to water and was not dried out fast.

Things like these should be taken into account before you do anything whether it is just a simple cleanup or a full-on disassembly.

Remember, if you lawnmower is still under warranty, make sure to ask the company whether your machine is eligible for a clean-up.

Step 2.1: Take photos of the carburetor before you do anything

You may not see this step in other guides but you need to have photos of the machine before you do anything.

The reason for this is to have a reference later on what the machine should look like when you put everything back in case you fumble in putting back the parts together after.

Also, this is good for warranty purposes to show that your machine has acquired damage and unusual wear-and-tear even under normal usage.

Step 3: Remove air filter then clean it

All the air that is sucked inside goes through the air filter. Unless you are using your lawnmower in a clean and empty room, your filter will have a lot of dirt and sediments on it.

You can just use a damp rag if there is minimal dirt but use the blow function of your vaccuum to remove the dirt.

If the air filter on your lawnmower can be removed, it is better to remove it and clean it on its own.

This way, you can clean both sides and leave it for it to dry. You can now proceed without waiting for the air filter to dry.

Step 4: Closely look at the insides with a flashlight or a headlamp

Other people skip this and just glance at the internals. With a flaslight or a headlamp, you can FOCUS on all the parts one-by-one to you know what you are dealing with.

You do not want any surprises like an exposed wire which you can leave unattended if you have not seen it with a flashlight.

Also, most carburetors have a dark paint or gets dark over time. You miss out the rust, moss, or other discoloration inside if you do not use a flashlight.

Step 5: Look at the connecting wires in the carburetor

Wires are important, but they are delicate. Any slight tug of it could snap it and render the machine useless (for a while until you get a replacement wire or patch it up).

It can also cause serious injuries when an exposed wire touches another wire or some dried grass (which are flammable).

This is also a good practice in being a better homeowner and a “DIY mechanic.” You will be familiarized with how a machine works.

After all, once you understand the machine of a lawnmower, you will be familiarized with other machines like electric generators, motorbikes, and electric fans.

A common issue of a failing carburetor are old spark plugs. The coating may have worn out due to aging and does not receive electricity optimally.

Step 6: Remove all the dirt with an air-compressor gun

Over the days (or months) you have used with your lawnmower, there could be a build up of dirt and gunk inside and outside the carburetor.

Some are placed in hard-to-reach areas so instead of squeezing your hands in, why not use an air-compressor gun?You can easily dislodge any debris with this tool. However, you should not use it with the highest setting or even use an industrial air-compressor gun that are meant for heavier cleaning.

Step 7: Spray the insides with an aerosol cleaner

Do not be confused to use water in cleaning your carburetor. That would just ruin the machine for good. An aerosol cleaner is a machine-friendly that sticks to the surface for longer protection.

Now, this step requires turning on the machine. The reason is you need the cleaner to go through the machine so that even the internal parts are cleaned.

On the center of the carburetor, spray in pulse the lawn mower carburetor cleaner like this one while the machine is running. You can do this in 10-15 pulses and leave the machine running for a minute to ensure maximum coverage.

Turn off the engine and spray the carburetor’s throat thoroughly. The lower plate will also have dirt so give it a good spray after.

Step 8: Remove all the gunk and deposits manually

After blowing off the dirt with the air-compressor gun and spraying the aerosol cleaner, now is the time to use your hands and manually clean off leftover dirt.

Make sure your rag is damp, and not soaking wet, to easily wipe off any solid dirt. Also, after every wipe of a major dirt, rinse the rag and squeeze out the water to avoid spreading the dirt further on the carburetor.

Step 9: Inspect everything before finishing

When everything is done, make sure to check everything and spot-check important parts using a flashlight. You can see the photos you have taken earlier to see if everything is matching.

Test it and let it run for 5 to 10 minutes to see if anything has been affected by the cleaning. Usually, you will notice a smoother start (no chugging sound or shaking).

Additional tips

Here are some final tips for you to consider before cleaning the carburetor

• Maintain a regular schedule of partial cleaning (like this article is saying) and deep cleaning (removing the carburetor).
• Before you take the lawn mower that won’t start for repair or cleaning to the shop, make sure you know what the problem is. Some shops will exaggerate the problem and ask for a more expensive service fee.
• Use the right aerosol cleaner. A general purpose cleaner is fine in most situations but if you want the best cleaner, get the one dedicated to lawnmowers or small carburetors. The cleaner for your over or your bathroom’s disinfectant spray are not suitable for this type of cleaning.

Conclusion

At first, cleaning the carburetor can be intimidating. After all, not everyone is proficient with machines or have previous experience with it. This guide is to give you an overview of how the process works.

However, as some lawnmowers are built differently and some have different usage, the process may vary.

In some gas-powered weed eater trimmers, you may have the same issues. So you can do the same checks like the above. The differences may be that you have a 2-cycle or 4-cycle engine.

Always remember that cleaning without removing the carburetor is not a replacement to deep-cleaning the carburetor by removing it and even dismantling the parts.

Maintain your lawnmower and it will serve you and even your kids well.

Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.

How to Clean a Husqvarna Mower Carburetor: Step-By-Step

Your Husqvarna mower begins to run sluggish or doesn’t start. This can be a result of a dirty carburetor gumming up from running old fuel. When experiencing issues that are caused by a lack or air or a lack of fuel, one of many items on your mower you should look at is the carburetor.

Symptoms of a Bad Husqvarna Mower Carburetor

When your carburetor is acting up, it is no longer able to correctly regulate the fuel to air mixture required by your Husqvarna’s engine. You could experience these symptoms:

• Husqvarna mower won’t start
• Husqvarna backfires from running lean
• Husqvarna mower engine sputters and runs rough
• Husqvarna mower engine surges
• Husqvarna mower consumes too much fuel

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

Steps to Clean a Husqvarna Lawn Mower Carburetor

If you have a fuel system problem and have confirmed you are getting fuel to the carburetor, perform one more step to confirm you need to disassemble and clean your carburetor.

Spray carburetor cleaner into the air intake and start your Husqvarna mower. If your mower starts, runs and then dies, you must disassemble your carburetor and clean it.

Take Photos of Your Husqvarna Mower Carburetor

Most people have a cell phone available nearby. It probably has a camera on it making photo-taking a quick easy process. If you have one of these, you should use it to document steps.

Even if you have a great memory, I highly recommend you take multiple photos of your carburetor before and during the tear-down process.

You will be working with many small parts. It will be good to have photos to reference to make sure you put your carburetor back together the correct way. You’re better off taking these photos and not needing them over not having photos at all.

Shut off Your Husqvarna’s Fuel Supply

Stop the fuel flow on your Husqvarna lawn mower. Use the fuel shut-off valve located on the bottom of your fuel tank. If you don’t have a valve on your mower, crimp the fuel line.

Remove Your Husqvarna Mower Throttle Choke Cable

Detach the throttle and choke cables from your carburetor.

Remove your Husqvarna’s Air Filter Housing

Remove the hardware that attaches the carburetor to the air filter housing so it is detached.

Remove the Springs from Your Husqvarna Mower Carburetor

Slowly remove the springs from the carburetor. Do not stretch the springs or you’ll have to replace them. You may have to twist the carburetor a bit to get the springs to come off the carb.

Be careful not to rip the gasket between the engine block and the carburetor or you will have to replace it with a new gasket.

Remove the Bowl from Your Husqvarna Mower Carburetor

Now locate the bowl on the bottom of your carburetor. This is the place a small amount of fuel is collected once it leaves the fuel tank. Have a rag available to soak up any remaining fuel in the bowl.

Remove the screw located at the bottom of the bowl and lower the bowl to remove it from the carburetor. You will find a gasket located around the bowl. It looks like a rubber Band.

Do not get any carburetor cleaner or other substance on the gasket as it will ruin it. If you do, the gasket must be replaced before the bowl is reattached.

Check Your Husqvarna Carburetor of Clogged Holes in the Stem

You will find a stem that hangs down in the center of your Husqvarna’s carburetor. The holes in the stem can become clogged with the gumming of old fuel. With a flashlight to better see the holes, use a thick wire to unclog them.

Remove White Crusty Buildup and Gumming in Your Husqvarna Mower Carburetor

Check the other component in your carburetor along with the carburetor itself for additional gumming and a white crusty buildup.

Remove the gummy deposits along with as much of the crusty material as possible using a carburetor cleaner. Note: It is almost impossible to remove all the crusty material.

Reassembly Your Husqvarna Mower Carburetor

Once you have finished cleaning the carburetor in your Husqvarna lawn mower and ensured all the components are in good working order including your float needle and float, go ahead and reassemble the carburetor.

Reverse the steps you went through when you removed your carburetor. Use the photos you took earlier for reference.

Replace or Rebuild Your Husqvarna Carburetor When Cleaning is Unsuccessful

Sometimes cleaning your carburetor doesn’t make it carburetor function correctly. You may have small components in your carburetor that must be replaced or old fuel has caused so much damage you need to replace the carburetor.

Rebuild or replace your carburetor. You will need to have your engine model and spec available to ensure you order the correct part(s). Husqvarna uses other manufacturers’ small engines in their mowers.

You can order a replacement carburetor or rebuild kit online, at your local Husqvarna dealership, or at an authorized engine dealership.

Fill Your Husqvarna Fuel Tank with Fresh Gas and a Fuel Additive

Run a good supply of fresh gasoline through your gas-powered Husqvarna lawn mower. Don’t let it sit in your mower for long periods of time.

Use a fuel additive to stabilize your fuel system to minimize future fuel issues. Read more about using Sea Foam Motor Treatment as a fuel stabilizer and why it is what I use in my lawn mower.

Cleaning Your Husqvarna Carburetor Didn’t Solve Your Problem

If cleaning your carburetor didn’t solve your problem and you still have problems in your fuel system. Check out my article Why Your Husqvarna Lawn Mower Isn’t Getting Fuel.

If you aren’t sure it is a fuel system problem, I have put together a list of common Husqvarna problems and solutions where I address starting, fuel system, smoking, overheating, cutting problems, and more. You can find it at Common Husqvarna Lawn Mower Problems Solutions.

Still Having Problems with Your Husqvarna Lawn Mower?

If you are still having problems with your mower, check out my guide on common problems owners encounter with their lawn mowers.

I put together a chart to identify causes and solutions to problems including starting, smoking, cutting, vibrating, dying, and more.

If you don’t feel comfortable troubleshooting and performing repairs on your lawn mower, it’s best to contact your local Husqvarna dealership or lawn mower repair shop for assistance.

You must remain safe and only perform repairs you are mechanically able to perform to avoid injury or further damage to the mower.

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