So Fix it

Carburetor cleaner is designed to remove heavy varnish and gunk from the inside and outside of a vehicles carburetor. If the carburetor is not cleaned periodically, it will begin to affect the vehicles mileage and performance. The carb should be cleaned a couple of times a year to prevent buildup and keep the engine running smooth.

Instructions

1

Remove the air cleaner unit from the engine by unscrewing the wing nut. You might need pliers to turn the wing nut if it is very tight.

2

Vacuum off the top of the engine area to prevent dirt and debris from being sucked into the engine while the air cleaner is not in place.

3

Spray the entire carburetor inside and out with carburetor cleaner to loosen the gunk and varnish. Use shop rags to wipe up any heavy grease and gunk loosened by the carb cleaner.

4

Start the vehicle. With the vehicle running, spray carburetor cleaner down the throat of the carburetor and around the outside. The engine will pick up a bit as the vehicle burns the carburetor cleaner. Wait a few minutes and shut off the engine.

5

Spray the outside and inside of the carburetor again heavily. Start the vehicle again and spray more carb cleaner around the outside and inside while the engine is running.

6

Spray the entire air cleaner inside and out with carburetor cleaner. Wipe the air cleaner dry with shop towels. Install a new air filter element and re-install the air cleaner unit onto the carburetor.

Motorcycle carburetors take in air and mix it with fuel. Numerous factors can throw a motorcycle carburetor out of tune. Typically, motorcycle carburetors are shaken out of tune by vibration. Manufacturers like Mikuni, Keihin and S & S sell original equipment and aftermarket carburetors for numerous motorcycles. Details vary but tuning principles are the same for all these devices. Here, specifically, is how to tune the carburetor Harley-Davidson has used since 1989.

Instructions

1

Remove the air cleaner cover with an Allen wrench. Loosen the air cleaner with a Torx wrench.

2

Disconnect the two breather tubes from the top of the air cleaner with your hands. Remove the air cleaner. Remove the air cleaner backing plate with a socket wrench.

3

Put the motorcycle in neutral. Start the motorcycle and let it run until the engine is hot. Leave the engine running during the following procedures.

4

Spray short bursts of aerosol carburetor cleaner into the venturi (the open mouth) of the carburetor. Allow the engine to stumble and recover. Then repeat.

5

Turn the idle speed adjuster screw next to the throttle cam with a flat head screwdriver until the engine idles smoothly without stumbling at the lowest possible engine revolutions per minute. Turn the screw clockwise to reduce idle speed and counterclockwise to increase idle speed.

6

Turn the low speed, fuel-air mixture screw on the bottom of the carburetor 1/8 clockwise. Wait five seconds for the idle to stabilize.

7

Continue to turn the low-speed screw clockwise 1/8 turn at a time with a five-second pause between turns until the engine stumbles and drops revolutions per minute. When the engine stumbles, turn the low-speed screw counterclockwise 1/8 turn.

8

Wait five seconds, then open the throttle. The engine should idle cleanly and respond without stumbling when you open the throttle.

9

Repeat adjustments to the idle speed adjuster screw and the low-speed, fuel-air mixture screw as needed until the engine idles cleanly at low speed and responds without stumbling when you open the throttle.

10

Turn off the motorcycle. Reinstall the air cleaner backing plate, the air cleaner, the breather tubes and the air cleaner cover.

Because most vehicles rely on a combustion for their power, the carburetor plays a truly critical role. In managing the blending of air and fuel, carburetors may need spacers to perform better and to maximize that mixing process.

Significance

The principle function of your carburetor is to mix air and fuel, thus aiding in the combustion process. Sometimes, the mixture streams velocity can be decreased, leading to a less efficient and less dynamic performance. The installation of carburetor spacers may help in re-establishing or enhancing that velocity.

Identification

Carburetor spacers are often constructed of wooden materials--such as plywood-- and then coated with a resin-like seal. They are placed in between the carburetor and the intake manifold plenum. In creating this space between the two, the spacers may aid in liberalizing the flow of the mixture stream, thus increasing its velocity.

Considerations

Because spacers contribute to an increased distance between the carburetor and the manifold unit, the signal of the carburetor may be compromised or weakened at the expense of the greater velocity. In order to remedy this, you maybe able to install stronger jets This is especially the case if you are using a four-holed spacer model as opposed to the open design.

A VM carburetor, which is also known as a round slide carburetor, is a special type of carburetor that is produced exclusively by the Mikuni Company of Japan.

Significance

A VM carburetor is a type of carburetor produced by the Mikuni company of Japan as a performance part for motorcycles and all terrain vehicles. The Mikuni VM carburetors are considered to be the most popular performance carburetors in single-cylinder motorcycle and all-terrain vehicle events, as of 2010.

Function

The main function of a VM carburetor is much the same as it is for any other carburetor -- to blend air and fuel together in an internal combustion engine. The VM carburetor can be tuned to allow changes to the air-fuel mixture, which also allows for many different levels of performance for different conditions.

Features

The Mikuni VM style of carburetors comes in a wide range of sizes. The main bore can range from as little as 1.73 inches wide to as large as 39 inches wide. The carburetors bodies are usually constructed from aluminum or zinc, with the main jet installed so that it can be replaced easily.

A carburetor combines fuel and air for the internal combustion engine of a motor vehicle. This device can have a single barrel, two barrels or four barrels. A single-barrel carburetor is commonly used on small engines that do not need large amounts of fuel and air. More barrels are only needed when there is a high rate of air flow and fuel displacement.

Single-Barrel Downdraft Carburetor

The single-barrel downdraft carburetor is one of the most common types of single barrel carburetors. These carburetors are suitable for engines requiring low air velocity and containing more air passages. Single-barrel downdraft carburetors use gravity to push the mixture of air and fuel into the cylinder.

Natural or Side Draft Carburetor

Natural or side draft single-barrel carburetors are best suited for use in small spaces above the engine. Unlike the downdraft carburetor, these types of carburetor move the air horizontally into the devices manifolds, which supply the air and fuel mixture to the cylinder.

Updraft Carburetor

The third type of single-barrel carburetor is the updraft carburetor. This type has been replaced by the aforementioned carburetors but some older cars still use them. The updraft carburetor is placed below the engine. Gravity forces the fuel from the tank above into the carburetor below. However, the air and fuel mixture must still be pushed upward into the engine.