Learn All About Carburetor

A carburetor is a device that mixes the air and fuel for internal combustion engines in the proper air-fuel ratio for combustion. This device is utilized in the spark-ignition engine so that the air-fuel can be mixed in the right ratio outside the cylinder. This process is also called carburetion.

There are different engines and all of them require the use of various carburetor types. Have a look at the following types of carburetors:

1. One-, Two-, and Four-Barrel Carburetors - There are a lot of ways to classify the divergent types of carburetors, and out of that one way is to count the number of barrels they contain. Carburetors come in one-, two- and four-barrel models.

2. Two-Barrel Subtypes - Two-barrel carburetors can be further divided into two types. In the first model, each barrel would contain all the required circuitry of a carburetor as well as a single common float chamber. Now when it comes to the second type, it is a bit more complicated. A single set of circuitry is shared by the two barrels and then each throttle would open at divergent times.

3. Side and Downdraft Carburetors - Side draft carburetors allow the air to flow in horizontally and are effortlessly mounted on engines where the space is limited.

Here are some essential features of a carburetor:

• Simple carburetors are inexpensive as compared to Electronic Fuel Injection (EFI).
• They should have fine adjustments according to the environment.
• The simple carburetor is a mechanical device, and it should respond uniquely in every possible adjustment.
• There should be no restriction on the amount of fuel drawn to the cylinder from the float chamber.
• It should provide a denser mixture at high speed for great power.
• Effortless and inexpensive carburetor repair maintenance.
• Carburetor automobiles would show more power and precision in the road test.

It is very important to know the working of a car carburetor since it is responsible for mixing gasoline and air in the correct amount and then getting that mixture into the cylinders. So have a look at its working below:

The air flows into the top of the carburetor from the car's air intake and then it passes through a filter that cleans all the debris. Now when the car engine is started, then the choke can be set, so it blocks the top of the pipe so that the amount which is coming in can be reduced. Now in the center of the tube, the air is forced through a narrow kink which is known as venturi. This would make it speed up and then the pressure would be dropped. 

Suction is created in the fuel pipe by the drop-in air pressure, which draws in fuel. The throttle is a valve that swivels to open or close the pipe. Now when the throttle is open, more amounts of air and the fuel flows to the cylinders, so the car engine produces more power and the car goes faster. The mixture of air and fuel flows down into the cylinders. Fuel is then supplied from a mini fuel tank which is known as a float-feed chamber. 

The carburetor comprises a float that rises and drops with the level of fuel in the float chamber of the carburetor. Now when the level of fuel falls, a float in the chamber also falls and then the valve at the top is opened up. When the valve opens up, more amount of fuel starts flowing into the float chamber. This makes the float rise and then the valve is closed again.

Some of the carburetor problems are mentioned below as follows:

1. Flooding - The issue of flooding in the carburetor starts occurring when there is a lot of flow of petrol from the main jet. This can be caused because of (i) a lot of petrol pressure in the float chamber on account of the fuel pump, (ii) the level of jet might be less than that of the float chamber, because of inappropriate fitting, causing natural flow, and (Hi) defective float providing a high level of petrol in the float chamber.

2. Engine Hunting - This issue starts appearing when the car engine runs in a series of surges and the speed of the engine starts fluctuating intermittently. This problem can be corrected by adjusting the slow-running air screw.

3. Popping Back - Explosions in the carburetor with a characteristic spitting or roughing sound occur as a result of a poor mixture, delayed ignition, faulty inlet valve seating, or weak or damaged valve springs. Because of incomplete combustion, cold engines are more susceptible to this issue.
4. Back Firing - When partially burned or unburned gas enters the exhaust manifold and comes in contact with ambient air, it burns in the silencer. This could be caused by a malfunctioning exhaust valve or a poor slow-running mixture.

If there are faults in the carburetor, then the automobile displays any of the following warning signs to alert the driver of a potential problem:

1. Reduced engine performance - The first symptom which is generally related to the faulty carburetor is a reduction in engine performance.

2. Black smoke from exhaust - One another symptom that is commonly related to a defective carburetor is the black smoke coming from the car exhaust. If there is black smoke coming from the exhaust, then it indicates that the engine is running excessively rich, or utilizing a lot of fuel.

3. Backfiring or overheating - Engine backfiring as well as overheating are other common symptoms that indicate that there are some flaws in the carburetor.
4. Hard starting - Hard starting is another symptom that is generally related to the failure in the carburetor.

Several skilled auto mechanics have a goal of opening their car repair shop in their career. But let’s face it; if you want to put up an efficient and profit-making shop, then you might need much more than mechanical skills. There are several tools that you might need to perform the car repairs quickly as well as reliably. Auto repair equipment that you will need to repair your Carburetor may include:

• Camera
• Extension set
• Flare nut wrenches
• Light solvents, such as brake clean or alcohol
• Marker
• Masking tape
• Pliers
• Scraper or razor blade
• Screwdrivers
• Shop rags or towels
• Small fuel-safe bowl or tray
• Small pry bar
• Socket set
• Wrench set

If you know which car parts brand suits the best for your Carburetor, then it will save a lot of your decision-making time. What we believe is that picking a particular brand will always help reduce the clutter, and will make it easier for the customers to find what they are looking for. That’s why we have listed out some top brands for Carburetor below:-

• Autoline Products Ltd Carburetors
• Quick Fuel Technology Carburetors 
• Champion Parts Carburetors
• Edelbrock Carburetors
• Holley Carburetors

If you are like most of us, then you won’t know much about the related components of car Carburetor. Fear not! Here is a quick and easy guide to explain the related parts of the Carburetor.

• Carburetor Boots/Clamp
• Carburetor Stud
• Carburetor Gasket
• Fuel Lines And Gauges
• Throttle Body
• Rebuild Kit
• Adapters & Spacers
• Air Filter
• Choke
• Metering Block Plates And Conversion Kits

There are a lot of factors that should be considered when you are thinking of replacing a Carburetor. First, decide if you require some related parts of a Carburetor or a whole Carburetor. Then after that, the next step is to decide what type of make and the type of Carburetor you are dealing with, and then from where will you get a brand new one. Just keep in mind that a brand new Carburetor that would come from a warehouse would cost much more than the one you will get in a junkyard. After that, the next point which should be considered is where you are going to get it replaced and how quickly it needs to be done. Normally, the cost of repair for your car carburetor can range from $200 to $300 and, if replaced, it can cost between $500 to $800.

Keen to know about the procedure of changing the Carburetor? Well, we have simplified the entire procedure for you:

Step 1

First, the battery cables should be disconnected. The car battery should be located and then cables should be removed. Shield the cables in a way so that they won’t be able to contact the posts on the car battery while the repairs are made. The cable terminals should then be covered and then you should secure them out of the way.

Step 2

There are a lot of carburetors that have an air cleaner assembly which covers the air intake side of the carburetor. It houses an air filter so that the dirt, as well as debris, can be kept out of the engine. Identify the air cleaner assembly as well as all the associated ductwork. Then the air cleaner assembly, as well as all the ductwork, should be removed. This can be done by utilizing the tools as per the type of fastener which would hold the parts in place.

Step 3

Identify and then remove all the vacuum hoses and other connections. All the hoses which are attached to the carburetor should be visually identified. The perimeter of the carburetor should be looked around and then all the hoses which connect to it should be identified.

Tip: It will be a great idea to take pictures of the hoses with the real configuration. This can be done by using a phone or camera as you can always refer back to the pictures which you have taken during the time of reassembly. You can always label the hoses and connections by using a masking tape and a marker. This can be done so that one can remember the place and the function of each one. Then all the hoses which are attached to the carburetor should be removed and then they should be secured off to the side of your working area.

Step 4

If there are any linkages, then they should be removed. The throttle linkage which connects to the throttle pedal inside the automobile should be located. The butterfly valve on the carburetor is controlled by this linkage. The amount of air that enters the carburetor is then controlled by the butterfly valve. Thus, it signals the amount of fuel that is required by the car engine. The linkage and its bracket should be visually identified. Then the throttle linkage should be disconnected as well as the bracketry which is mounted to the side of the carburetor.

Step 5

The fuel supply line should be carefully disconnected. The fuel from the fuel tank is used by the carburetor so that the gasoline can be supplied to the car engine. There is a tube or a metal hose for this, which is known as the fuel supply line, which then connects to the carburetor. Now if there is any residual fuel pressure in the fuel line, then they should be released. The fuel supply line should then be drained so that the leakages can be avoided. After that, the fuel supply line should be moved off to the side.

Step 6

Then it is essential to remove the old carburetor. A combination of bolts, nuts, studs and screws should be held onto the intake manifold by the carburetor. Such fasteners might be situated on the carburetor. The carburetor mounting hardware should be identified and removed. Then the right tools should be utilized so that the mounting hardware can be removed. The carburetor should be set free from the intake manifold.

Warning: Just be very careful when you pry on the carburetor as the body and flanges are fragile. That is the reason why they might get defective or break if caution is not taken. Nothing should be forced into the seam between the intake manifold and the carburetor.

The intake manifold opening should then be blocked off. Shop rags or towels should be placed in the intake's opening manifold so that the debris which is falling can be avoided. After that, the old gasket should be carefully removed.

Note: Not all manufacturers would utilize use a gasket.

Tip: If the gasket sticks to the surface of the carburetor or the intake manifold, then the gasket should be removed by using the scraper or razor.

Step 7

After that, prepare to install the replacement carburetor. Then the carburetor and the intake manifold mounting flanges should be cleaned. All the dirt, as well as debris, should be removed so that the seal is leak-free. After that, the new carburetor gasket should be carefully installed.

The old carburetor should then be compared to the new one. You can always spend a few minutes to visually inspect both of them. The parts should then be transferred from the original carburetor to the brand new one. If there are any shop rags or towels, then they should be removed.

Step 8

The replacement carburetor should then be installed. And placed back onto the intake manifold. Then the installation process of the carburetor should be completed.

Step 9

The carburetor should be carefully inspected for leakages. Now once the carburetor has been installed properly, then it is essential to check the system for any leakages. The battery cables should then be reconnected. The pressure should then be built upon the carburetor as it totally depends upon the type of the car fuel system. Fuel pressure should then be applied to the system.

Note: The automobiles which have an electric fuel pump need the ignition key to be placed into the run position and then the leakage should be checked. The automobiles which have a mechanical fuel pump might need the engine to be cranked before the pressure of the fuel can be achieved. There might not be a need to run the car engine, it might be just cranked long enough so that the pressure can be built up in the lines to inspect the leakages. 

Tip: You must carefully listen to the whistling sound which comes around the carburetor. It might also show some leakages in the vacuum.

Warning: Now if the leak is detected, then the car engine should be shut off immediately, and just be careful that there should be no sparks. If there will be any spilled fuel, then it should be cleaned as soon as possible.

If there are any leakages, then they should be repaired properly. Any fittings or fasteners should be tightened as per the need to seal the leakages. Then the car engine should be started once again. Then the functioning of the new carburetor should be inspected.