As an owner of a two-wheeler motorcycle alias, have often heard the term "carburetor". Although already familiar with this term, it is still quite a lot of motorcycle owners also do not understand about the function of these devices is vital. Especially novice rider category that lay on the motor, how the carburetor and how to set it often gets confused.
Here's a basic description of how the carburetor motor summarized from various sources and references, can hopefully help fellow newbie who do not quite understand about the workings of a carburetor.
1 Carburetor Function
As the combustion engine, we know that our motor fuel it needs to be able to start and operate (as well as the compression and fire). Well this is the carburetor main brain that are responsible for the supply / supply fuel to the engine of our continuity of operations. Definition of 'fuel' does not just gasoline, but rather in the form of gasoline + air mixture in a particular composition. So you can not start the engine by means of flush / pour gasoline directly from the tank into the engine combustion chamber. Instead of life, that there is even a motor drenched us.
This is where the role of the carburetor needed, because the carburetor is designed to produce gasoline + air mixture is burned in the combustion chamber READY engine, ready to burn. That is by breaking the existing gasoline carburetor bowl into small particles (atomized spray system as well as the perfume spray / insect repellent) and then mix it with oxygen particles from the outside air, and then send the ready fuel mixture into the engine.
2 Mixture Ratio / Air Fuel Ratio (AFR)
To be burned properly, the fuel and air must be mixed in a certain amount of comparison or composition, or a fancy term Mixture Ratio Air Fuel Ratio (AFR). The composition or the ratio of the ideal air + fuel for combustion engines according to the theory is the air 14,7gr for every 1 gram of gasoline (14.7: 1). Although in practice it may not always get a fixed rate for the engine's internal condition and external environmental conditions that dynamic aliases can change that affects the supply of carburetor mixture, so the range of 12: 1 to 15: 1 could be categorized ideal.
Ideal composition means that the composition of the gas + air that can be burned in engines allows without leaving residual gas or residual air that does not burn, in other words Burned completed. From this arises then popular term that we often hear in discussions about setting the carburetor; namely "wet settings vs. dry settings" or "rich mixture of mixtures vs. poor".
Wet settings (rich mixture) means that the composition of the air less than ideal conditions, such as air 10gr: 1 gram of gasoline (AFR 10: 1). Dry settings (lean mixture) means that the composition of more air than ideal conditions, such as air 17gr: 1 gram of gasoline. Settings wetness makes too much fuel than the air entering the engine, so that when the rest of the gas leaving the combustion of unburnt. Settings drought yes contrary, at the time of leaving the rest of the combustion air is burned in the engine failed. Therefore, efforts to obtain the composition of the gas mixture of air + Ideal reply so this is actually the main goal of "setting the carburetor 'or also called jetting.
So how can we know that the air fuel mixture carburetor we have an ideal? Indeed, there is a tool called AFR Meter measuring, but because not many people have this tool, most of the riders or more frequently diagnose AFR tuner to recognize and experience the symptoms in the engine, also with the help of reading spark plugs sighting conditions.
3 Working Principle Carburetor
The working principle is actually quite simple carburetor is to use two basic principles:
a. The principle of air pressure / atmospheric pressure.
Maybe viewers still remember a bit of time whether it's science lessons sd, smp or sma, which states that the air will move or flow by itself from somewhere that the higher pressure towards lower pressure which places. Well, the 4 stroke engine, aka 4 steps, vacuum / low pressure is created in the cylinder chamber during suction step (piston moves from (top dead center) to TDP (Bottom Dead Point) BDP). Because the air pressure outside the cylinder is higher, then the air will move from outside the carburetor past the hallway, past the intake, ported channels, and valve IN currently open to the cylinder and then fill the space there so that eventually the air pressure in the cylinder back into balance with the air pressure outside the cylinder . Now moving air flow from the outside through the alleys of the carburetor is then used as a transport medium for transporting or carrying gasoline and fog produced carburetors.
b. The principle of the venturi effect (Venturi Effect)
Hallway / main channel in the carburetor called a Venturi. Venturi has several sizes such as standard Satria FU carburetor (Mikuni BS26) which has a diameter of 26mm venturi, or Keihin PE28 carburetor venturi which has a diameter of 28mm.
Wider hallways designed carburetor in the carburetor and narrow in muzzle so that airflow can move quickly when entering the venturi. Since the air flow will move faster when it comes to passing a smaller space. As well as the flow of water in the swift current of the river that enters the river narrows. Or heavy water flowing over the smaller hose. Physics Rule also states that the faster flow or air flow sector in space, then the air pressure her even more down in the space. Based on this principle, the air is moving fast along the corridor venturi causing the air pressure inside the hall venture to be down, lower than normal air pressure inside the carburetor bowl (values range from 15psi normal atmospheric pressure, so there are ventilation holes in the carburetor bowl to keep the pressure remains normal in bowl).
Well, the pressure difference across the aisle with the venturi in the carburetor bowl allows the gas from flowing up the bowl like sucked up into the hall and come mixed with venturi air flow to the engine there.
4 Types and Construction Carburetor
There are two types of carburetors types that most often we encounter the type of carburetor vacuum (Constant Velocity Carburetor) example yes FU standard carburetor, Mikuni BS26. And one more that conventional carburetors or carburetor also called Skep (Slide Carburetor / Carburetor Variable Venturi) carburetor Keihin PE28 example is, PWK28, Mikuni VM28, etc..
Two types of carburetor is actually still working on the same principle as described in the above section (the principle of air pressure and the venturi effect), it's just that there is little difference in the mechanism of setting up and down his skepticism. Conventional carburetor up and down skepticism directly connected to the throttle cable, whereas in the carburetor vacuum, up and down skepticism is not directly connected to the throttle, but through intermediaries butterfly valve first. Henceforth, to make it more easily understood, I use illustrations to pinch more than conventional carburetors / skepticism because I think it is simpler and can be more easily digested by the reader.
As we know, our motorcycle operations are used dynamically. Each of the different uses of this course requires the amount of fuel supply also varies. Supply high speed would require more fuel than at low speeds, and vice versa.
For this reason the construction of a carburetor designed by its engineers so that they can meet the fuel supply to dynamically adapt to the needs of the varying use of the machine. In the carburetor, there are several paths or technical term called 'metering circuit', which track the path that serves to "metering" or adjust the amount of fuel + air discharge to be sent to the machine. For practical reasons the discussion here, we will narrow down the metering mechanism of this circuit into two circuits are only the most important for the purposes of setting the pilot circuit and Main Circuit. Actually, there was something else such as a starter circuit, but it is only intended to facilitate combustion conditions when the engine is cold, so we leave it first.
Then how a carburetor can determine which circuit should be activated to serve the ever-dynamic engine? That is, with reference to the forces that rise and fall according skepticism twist throttle. It should be stressed here that the circuit where the play will be determined by how high class of skepticism (how deep you open the throttle at the time), is not determined by the rotation of the engine / RPM.
The term low speed, medium or high is not a 'cause', but a 'result' or the effect of variations in the amount of fuel going into the engine. The position of skepticism forces who actually serves as a regulator of barrier / restriction of air flow that can pass through the hall venturi carburetor, by itself jg set low air pressure that is needed to pull the gas out of the bowl.
5. Pilot Circuit
Role of openings 0 (Langsam) s.d. ¼ openings skepticism. The pilot circuit is also often referred to as Low Speed System, because it had taken effect at the time of the motor driven at low speeds. The parts of the pilot circuit is:
Jet Pilot, serves as a gas discharge lines from the bowl to the venturi. Available with a variety of hole sizes numbers. The larger the size, the more the amount of gasoline that can get through the pilot jet. For example, the standard carburetor pilot jet size 12.5 FU
Here's a basic description of how the carburetor motor summarized from various sources and references, can hopefully help fellow newbie who do not quite understand about the workings of a carburetor.
1 Carburetor Function
As the combustion engine, we know that our motor fuel it needs to be able to start and operate (as well as the compression and fire). Well this is the carburetor main brain that are responsible for the supply / supply fuel to the engine of our continuity of operations. Definition of 'fuel' does not just gasoline, but rather in the form of gasoline + air mixture in a particular composition. So you can not start the engine by means of flush / pour gasoline directly from the tank into the engine combustion chamber. Instead of life, that there is even a motor drenched us.
This is where the role of the carburetor needed, because the carburetor is designed to produce gasoline + air mixture is burned in the combustion chamber READY engine, ready to burn. That is by breaking the existing gasoline carburetor bowl into small particles (atomized spray system as well as the perfume spray / insect repellent) and then mix it with oxygen particles from the outside air, and then send the ready fuel mixture into the engine.
2 Mixture Ratio / Air Fuel Ratio (AFR)
To be burned properly, the fuel and air must be mixed in a certain amount of comparison or composition, or a fancy term Mixture Ratio Air Fuel Ratio (AFR). The composition or the ratio of the ideal air + fuel for combustion engines according to the theory is the air 14,7gr for every 1 gram of gasoline (14.7: 1). Although in practice it may not always get a fixed rate for the engine's internal condition and external environmental conditions that dynamic aliases can change that affects the supply of carburetor mixture, so the range of 12: 1 to 15: 1 could be categorized ideal.
Ideal composition means that the composition of the gas + air that can be burned in engines allows without leaving residual gas or residual air that does not burn, in other words Burned completed. From this arises then popular term that we often hear in discussions about setting the carburetor; namely "wet settings vs. dry settings" or "rich mixture of mixtures vs. poor".
Wet settings (rich mixture) means that the composition of the air less than ideal conditions, such as air 10gr: 1 gram of gasoline (AFR 10: 1). Dry settings (lean mixture) means that the composition of more air than ideal conditions, such as air 17gr: 1 gram of gasoline. Settings wetness makes too much fuel than the air entering the engine, so that when the rest of the gas leaving the combustion of unburnt. Settings drought yes contrary, at the time of leaving the rest of the combustion air is burned in the engine failed. Therefore, efforts to obtain the composition of the gas mixture of air + Ideal reply so this is actually the main goal of "setting the carburetor 'or also called jetting.
So how can we know that the air fuel mixture carburetor we have an ideal? Indeed, there is a tool called AFR Meter measuring, but because not many people have this tool, most of the riders or more frequently diagnose AFR tuner to recognize and experience the symptoms in the engine, also with the help of reading spark plugs sighting conditions.
3 Working Principle Carburetor
The working principle is actually quite simple carburetor is to use two basic principles:
a. The principle of air pressure / atmospheric pressure.
Maybe viewers still remember a bit of time whether it's science lessons sd, smp or sma, which states that the air will move or flow by itself from somewhere that the higher pressure towards lower pressure which places. Well, the 4 stroke engine, aka 4 steps, vacuum / low pressure is created in the cylinder chamber during suction step (piston moves from (top dead center) to TDP (Bottom Dead Point) BDP). Because the air pressure outside the cylinder is higher, then the air will move from outside the carburetor past the hallway, past the intake, ported channels, and valve IN currently open to the cylinder and then fill the space there so that eventually the air pressure in the cylinder back into balance with the air pressure outside the cylinder . Now moving air flow from the outside through the alleys of the carburetor is then used as a transport medium for transporting or carrying gasoline and fog produced carburetors.
Hallway / main channel in the carburetor called a Venturi. Venturi has several sizes such as standard Satria FU carburetor (Mikuni BS26) which has a diameter of 26mm venturi, or Keihin PE28 carburetor venturi which has a diameter of 28mm.
Wider hallways designed carburetor in the carburetor and narrow in muzzle so that airflow can move quickly when entering the venturi. Since the air flow will move faster when it comes to passing a smaller space. As well as the flow of water in the swift current of the river that enters the river narrows. Or heavy water flowing over the smaller hose. Physics Rule also states that the faster flow or air flow sector in space, then the air pressure her even more down in the space. Based on this principle, the air is moving fast along the corridor venturi causing the air pressure inside the hall venture to be down, lower than normal air pressure inside the carburetor bowl (values range from 15psi normal atmospheric pressure, so there are ventilation holes in the carburetor bowl to keep the pressure remains normal in bowl).
Well, the pressure difference across the aisle with the venturi in the carburetor bowl allows the gas from flowing up the bowl like sucked up into the hall and come mixed with venturi air flow to the engine there.
There are two types of carburetors types that most often we encounter the type of carburetor vacuum (Constant Velocity Carburetor) example yes FU standard carburetor, Mikuni BS26. And one more that conventional carburetors or carburetor also called Skep (Slide Carburetor / Carburetor Variable Venturi) carburetor Keihin PE28 example is, PWK28, Mikuni VM28, etc..
Two types of carburetor is actually still working on the same principle as described in the above section (the principle of air pressure and the venturi effect), it's just that there is little difference in the mechanism of setting up and down his skepticism. Conventional carburetor up and down skepticism directly connected to the throttle cable, whereas in the carburetor vacuum, up and down skepticism is not directly connected to the throttle, but through intermediaries butterfly valve first. Henceforth, to make it more easily understood, I use illustrations to pinch more than conventional carburetors / skepticism because I think it is simpler and can be more easily digested by the reader.
For this reason the construction of a carburetor designed by its engineers so that they can meet the fuel supply to dynamically adapt to the needs of the varying use of the machine. In the carburetor, there are several paths or technical term called 'metering circuit', which track the path that serves to "metering" or adjust the amount of fuel + air discharge to be sent to the machine. For practical reasons the discussion here, we will narrow down the metering mechanism of this circuit into two circuits are only the most important for the purposes of setting the pilot circuit and Main Circuit. Actually, there was something else such as a starter circuit, but it is only intended to facilitate combustion conditions when the engine is cold, so we leave it first.
Then how a carburetor can determine which circuit should be activated to serve the ever-dynamic engine? That is, with reference to the forces that rise and fall according skepticism twist throttle. It should be stressed here that the circuit where the play will be determined by how high class of skepticism (how deep you open the throttle at the time), is not determined by the rotation of the engine / RPM.
The term low speed, medium or high is not a 'cause', but a 'result' or the effect of variations in the amount of fuel going into the engine. The position of skepticism forces who actually serves as a regulator of barrier / restriction of air flow that can pass through the hall venturi carburetor, by itself jg set low air pressure that is needed to pull the gas out of the bowl.
Role of openings 0 (Langsam) s.d. ¼ openings skepticism. The pilot circuit is also often referred to as Low Speed System, because it had taken effect at the time of the motor driven at low speeds. The parts of the pilot circuit is:
Jet Pilot, serves as a gas discharge lines from the bowl to the venturi. Available with a variety of hole sizes numbers. The larger the size, the more the amount of gasoline that can get through the pilot jet. For example, the standard carburetor pilot jet size 12.5 FU
. 
At the time of skepticism is still closed from idling to full height ¼ force, at that time there was little gap just below the skepticism that is available in the hallway carburetor air flows. Less air flow is not sufficient to create a low pressure in the hallway carburetor needed to pull fuel out of the main line of the main jet. This requires a special circuit paths that can still supply the mixture to the engine, the pilot lines from the bowl to supply jet fuel, combined with the water lines from nose bleed carburetor which supplies air to facilitate gas carburetion.
Total gasoline set size pilot jet, air amount set screw openings suit wind / water screw. This estuary discharge lines near the venturi / 2 way manifold with exit holes, the pilot hole outlets are located outside of the lips skepticism, and the bypass hole is located just inside the lip skepticism. By doing so, the pilot outlet unaffected despite skepticism fully closed. By simply relying on vacuum suction cylinder space, the pilot supply outlets still able to drain mixture needed to turn on the machine. But when skepticism slightly raised / open (idling), the flow of air from the hallway entrance of the gap began to increase skepticism. In this condition, the gas supply from the pilot outlet alone is not enough to offset the amount of air, to the gasoline supply shortages helped by additional supply from the bypass hole.
The mechanism is more complete than the pilot circuit can be analyzed from the following diagram
Skep Needle (Needle Jet): Part one of this would have been familiar for viewers. As the name implies yes shaped like a needle, a long rod that tapered at the ends. Needle skepticism serves as the opener and stopper gas exit path from the main jet to the venturi. In some types of carburetors, needle skepticism comes with a clip at the base setting to adjust the height of the needle, which affects the clearance (gap) between the needle and the cross-section which will be the path of the gas through the main jet to the venture. In addition to setting the clip height, gap or clearance is also influenced by the profile or shape of needle skepticism. Among the diameter of the needle (obese vs. lean), taper / taper needle (vs. steep ramps), designed with precision by the makers of the carburetor so that the difference was so micron effect on its clearance.
Nozzle (Jet Needle): is a pair of needle skepticism. The nozzle is shaped pipe which serves as a cross-section / glove / sleeve or trajectory for needle skepticism that moves up and down inside the nozzle. As with indentation skepticism (cutaway), nozzle also rarely changed foxes or touched upon carburetor settings. Because there is rarely a replacement part. In contrast to his partner that needle skepticism, easy to get the needle 'racing' which can be applied to replace the standard needle.
Main Jet: is the main exit of the gasoline carburetor bowl. Connected directly to the main jet nozzle. If the pilot jet role in low speed, then play a role for the high speed jet. As with the pilot jet, Main jet also has a number of various sizes. The larger the size of the main jet, the more fuel discharge that may be dispensed. Examples of standard size Main Jet carburetor adaah FU 110.
How does the mechanism of Main Circuit aka the main circuit is working?
By the time the gas is more twisted, skepticism rises above ¼ force, opening the door to more heavy airflow in the carburetor hallway. Low pressure created in this condition sufficient to draw fuel up from the bowl through the main jet. At the operational speed of this medium, how much amount of gas that can ride out to the venturi will be determined by the clearance gap blockage in the nozzle needle skepticism. The more up needle skepticism, the field is also a way out of the main jet fuel. Until finally when the rising skepticism force exceeds ¾ (full throttle), needle skepticism lifted completely from the nozzle, giving free space without barriers for the gas lines from the main jet. So that the condition gaspol or full throttle, the needle skepticism is no longer functioning, the gas discharge only a limited size of the main jet alone.
There should also note that the main circuit there is any water lines that separate jet stream portion of the snout carburetor air lines connected to the main jet / nozzle, but water jets can not be regulated by the airscrew couplers as well as jet water lines connected to the pilot jet. So before getting to the venturi, the gas passing through the main jet and nozzle already mixed first (atomized) with air supplied from the water jet path. This new mixture then joined the air flow in the hallway carburetor / venturi.
Viewers, since I've never had a Keihin PE28 carburetor popular article for example, at home there are in china carburetor just plug in my Satria FU.
Although simple, the role of the device is indeed vital. An understanding of the basic logic of this carburetor in my opinion needs to be completely understood by a rider or biker. By understanding the workings of the essence, at least we can more easily diagnose and find solutions when there are problems in the performance of our motorcycle carburetor.
Related settings or carburetor jetting, I think it would be too long if it is discussed here. Although I also still lacking experience about setting the carburetor, but let the next opportunity later on I'll try to write about the basics of motorcycle carburetor settings that can be applied by the rider lay as well as my own.
- Water Jet or Air Bleed, serves as the entry point of the muzzle carburetor air to be mixed with gasoline from the pilot jet. The amount of air that can pass through the channel is governed by a water jet adjustment bolt (adjustment screw). Usually there are 3 lanes on muzzle airbleed carburetor, the supply to the pilot jet, one to the main jet, and one lg to chuck system. As an example can be seen in the photo muzzle Shengwei carburetor which is a replica of the Mikuni VM30.
- Air Screw, A regulator screw (adjustment screw) that closes and opens pathways in the water bleed air passage leading to the pilot jet. But keep in mind that there are two types of adjustment screw. The first of these screw ya water, usually in 2-stroke motorcycle carburetor Keihin PE28 such, PWK 28, etc.. Air screw is located on the side near the muzzle carburetor bowl. While in 4-stroke motorcycle carburetor carburetor vacuum like FU, called Fuel Screw, screw instead of water. Because its function is already not only regulates the air, but rather regulate the discharge of gasoline which has been in the form of mixture (already mixed with air). The position of the screw is also different, is located near the venturi / manifold, not in the air near the muzzle.
Holes skepticism or slide cutaway. In practice carburetor settings in general, this section was barely touched or changed foxes, usually entrusted to the standard conditions. Holes skepticism is the open back end of skepticism. Despite skepticism fully closed, this part still providing space for air to enter. The larger the cutaway coakan or her, the more incoming air and mix the dry mixture. Effects of changes in the eighth cutaway felt until fourth skepticism, even to the half aperture skepticism as a transition into the middle rounds. However, because this part usually allowed to default, then the details will not be discussed in this article.
How does this actually work mechanism Circuit Pilot?
How does this actually work mechanism Circuit Pilot?
Total gasoline set size pilot jet, air amount set screw openings suit wind / water screw. This estuary discharge lines near the venturi / 2 way manifold with exit holes, the pilot hole outlets are located outside of the lips skepticism, and the bypass hole is located just inside the lip skepticism. By doing so, the pilot outlet unaffected despite skepticism fully closed. By simply relying on vacuum suction cylinder space, the pilot supply outlets still able to drain mixture needed to turn on the machine. But when skepticism slightly raised / open (idling), the flow of air from the hallway entrance of the gap began to increase skepticism. In this condition, the gas supply from the pilot outlet alone is not enough to offset the amount of air, to the gasoline supply shortages helped by additional supply from the bypass hole.
The mechanism is more complete than the pilot circuit can be analyzed from the following diagram
6 Main Circuit
Role of ¼ skepticism until full throttle opening (gas poll). Main circuit or the main circuit is also commonly referred to as High Speed System, because the speed strongly influences from medium to top speeds. Part - the part of the Main circuit consists of:
Role of ¼ skepticism until full throttle opening (gas poll). Main circuit or the main circuit is also commonly referred to as High Speed System, because the speed strongly influences from medium to top speeds. Part - the part of the Main circuit consists of:
Nozzle (Jet Needle): is a pair of needle skepticism. The nozzle is shaped pipe which serves as a cross-section / glove / sleeve or trajectory for needle skepticism that moves up and down inside the nozzle. As with indentation skepticism (cutaway), nozzle also rarely changed foxes or touched upon carburetor settings. Because there is rarely a replacement part. In contrast to his partner that needle skepticism, easy to get the needle 'racing' which can be applied to replace the standard needle.
Main Jet: is the main exit of the gasoline carburetor bowl. Connected directly to the main jet nozzle. If the pilot jet role in low speed, then play a role for the high speed jet. As with the pilot jet, Main jet also has a number of various sizes. The larger the size of the main jet, the more fuel discharge that may be dispensed. Examples of standard size Main Jet carburetor adaah FU 110.
How does the mechanism of Main Circuit aka the main circuit is working?
There should also note that the main circuit there is any water lines that separate jet stream portion of the snout carburetor air lines connected to the main jet / nozzle, but water jets can not be regulated by the airscrew couplers as well as jet water lines connected to the pilot jet. So before getting to the venturi, the gas passing through the main jet and nozzle already mixed first (atomized) with air supplied from the water jet path. This new mixture then joined the air flow in the hallway carburetor / venturi.
Viewers, since I've never had a Keihin PE28 carburetor popular article for example, at home there are in china carburetor just plug in my Satria FU.
Related settings or carburetor jetting, I think it would be too long if it is discussed here. Although I also still lacking experience about setting the carburetor, but let the next opportunity later on I'll try to write about the basics of motorcycle carburetor settings that can be applied by the rider lay as well as my own.
