SPARK PLUG

Picture 1.Busi

High voltage generated by the ignition coil secondary coil, after a series of high voltage between the electrodes will be excluded middle (positive electrode) and electrode side (negative electrode) plugs in the form of sparks. The purpose of this plug in is to flow the current pulses or high voltage from the cap (terminal) into the spark plug center electrode to the electrode side through the air gap and then ended the period (ground). Spark plug is a part (component) ignition system is biased low, designed to perform tasks within a specified time and must be replaced with new ones if the plugs are worn or eroded.

Construction Plugs
The top of the spark plug is a terminal that connects the high voltage cable. These terminals connect with the middle electrode is usually made from a mixture of nickel to withstand the heat and destructive elements in the fuel, and often has a copper core to help remove heat. In some electrode spark plugs are made from a mixture of silver, platinum, palladium or gold. -Spark plugs are designed to provide resistance to a greater erosion and can remain good.

Picture 2. Construction plugs

Central electrode through an insulator ceramics found on the outside. Isolator serves to protect the electrode from electrical leakage and protect from heat engines. To prevent gas leaks are seals between electrodes with an insulating middle and the body between the spark plug insulators.
Body plugs made of steel and nickel plate is usually given to prevent corrosion. The top of the hexagon-shaped outer body (the corner of the hexagon) which serves to harden (set up) and relax (open) spark plugs. At the bottom is made so that the screw can be screwed plugs (attached) to the cylinder head. At the bottom there is the spark plug electrode side or the negative electrode. This electrode spark plug is welded to the body to point to the time when there is a spark. There are two types of seat plugs are flat and cone shaped. Sparkplug holder is part of the body of the spark plug at the top screw that will meet / is paired with the cylinder head. If the spark plugs seat is flat, then there are the ring seals (sealing washer), on the other hand, if the cone-shaped holder does not require the ring seals.

Ability of generating sparks depends on several factors, among others, as follows:
a. Form electrode spark plugs
Round electrode spark plugs will make the leap sparks while square and pointed and sharp will make a stepping fire. The spark plug electrodes will be used in the round after a long time, therefore
sparks leap will be weak and cause ignition of error, otherwise the thin electrodes or sharp will make sparks, but use a short life due to faster wear


b. Spark Plug Gap
If the spark plug electrode gap larger sparks would be a difficult jump and the secondary voltage required for it would have been up. If worn spark plug electrodes, means the gap increases, sparks leap becomes more difficult so that will cause ignition fault.
Gap of electrodes for motorcycles (arrow in image at right) usually 0,6-0,7 mm (for details see the user manual or catalog spark plugs)

Figure in addition to the electrode gap is too small. This will result; weak spark, electrode dirty fast, especially on the 2 machines can not (two strokes).

Figure in addition to the electrode gap is too large. This will result in the need for jump voltage spark higher. Insulator-insulator high-voltage parts quickly damaged by the children brought up-ignition voltage extraordinary height.
If the ignition system can not meet these needs, the engine began life is choked up at full load.
In addition, the spark plug gap is too large can also cause the engine a bit difficult to start up.


c. Compression Pressure
If the compression pressure increases, the interest any will become increasingly difficult to jump and voltage required higher and higher, this also happens during heavy load and slow the vehicle Take a low-speed and fully open the gas valve. Required ignition voltage also rises when the temperature mixture of air-fuel down.

Ignition Coil Type

There are three main types of ignition coils used on motorcycles, namely:
1. Canister Type
This type has an iron core in the middle and secondary coil surrounding the iron core. Primary coil in the outside of the secondary coil. Overall the components are assembled in one house in a metal canister. Sometimes canister filled with oil (lubricant) to help reduce the heat coil.

Picture 1. Ignition coil Canister type

2. Molded Type
Molded coil type is the type commonly used now. In this type of iron core in the center surrounded by a primary coil, while the secondary coils are on the outside. Overall the components are assembled and then wrapped the resin (resin) to withstand the vibrations that are usually found in motorcycles. Type coil molded into a popular choice for the construction of resistant and strong. In multicylinder engine usually one coil serving two spark plugs because they have two high voltage wires from the secondary coil.

Picture 2. Ignition coil molded type

3. Integrated Ignition Coil Type With The Spark Plug Cap (Spark Plug)
This coil type is the most recent type and often referred to as the coil rod (stick coil). Large size and weight are smaller than the type of coil and molded most advantage of the coil does not require a high voltage cable.

Picture 3. Integrated ignition coil type with spark plug cap

Ignition Timing

During ignition of a mixture of gasoline and air is a time
of a spark plug spark some degree before top dead centre (TDC) at the end of the compression step. When the occurrence of spark
time must be determined appropriately so that you can burn
the perfect mix of gasoline and air in order to achieve energy
maximum.
After the mixture of fuel burned by fireworks, the
time required for fire to spread in the room
fuel. Therefore there will be a slight delay between the start
burning with the achievement of the maximum combustion pressure.
Thus, in order to obtain maximum output with the engine
combustion pressure reaches the highest point (about 100 after TDC),
the propagation of fire should be considered when determining
ignition timing.
Because requesting a time for propagation of fire, the
mixture of fuel - the air must have been burned before TDC. When
start of a burning mixture of fuel and air is
called the ignition time. So that when the ignition
can be adjusted with the speed, engine load and other
equipment needed to change (forward or rewind)
during ignition. One of them is to use
vacuum advancer and governor for the ignition advancer conventional.
In a motorcycle is usually called the (Automatic Timing Unit). ATU will
set during furtherance ignition. In the motorcycle with the system
conventional ignition (using platinum) ATU regulated
mechanics while the electronic ignition system ATU regulated
electronic. More explanation about ATU discussed in part I
(Type System ignition On Motorcycles).
When the ignition time moved forward too far, the maximum combustion pressure is achieved before 10o
after TDC. Because the pressure in the cylinder will become higher
from the burning time with the right mix for burning
air fuel that occurs spontaneously and ultimately will occur
knocking or detonation.
Knocking is an explosion that resulted in a wave
a surprise because the wage-pounding sound pressure and a large
going strong at the end of the burning. Knocking over will
cause the valves, spark plugs and piston burn. When the ignition
too forward can also cause the engine temperature becomes too high.
Meanwhile, when the ignition time retard too far then the maximum combustion pressure occurs will
after 10o after TDC (at which the piston has come down far enough). When
compared with the ignition timing is correct, then the pressure in the cylinder is rather low so that the engine output
decreased, and the waste of fuel and other will occurred. Ignition when the correct pressure can produce
optimal combustion.

ELECTRONIC FUEL INJECTION (EFI)

Type of fuel system is a step injection of innovation that are being developed to be applied to the bicycle machine. This type of injection is already applied to the bicycle in a limited number of machines in the 1980s, starting with a mechanical injection system evolved into the electronic injection system. Mechanical injection system is also called continuous injection system (K-Jetronic) because the injector is continuously sprayed into each inlet (intake manifolds). While electronic injection system or better known as Electronic Fuel Injection (EFI), the volume and time Injenction done electronically. EFI System sometimes referred to as EFI (Electronic Gasoline Injection), EPI (Electronic Gasoline Injection), PGM-FI (Programmed Fuel Injenction) and Engine Management. The use of fuel injection systems on the bike commercial engine in Indonesia has started to be developed. One example is on one type of production Astra Honda engine, which is the Supra X 125. Term EFI system on the Honda PGM-FI (Programmed Fuel Injection) or the fuel system has been programmed. In general, the replacement of conventional fuel systems to the EFI system is intended to increase performance and engine power a better, more stable acceletation at every turn the engine, fuel consumption is economical, and produce emissions that the exhaust gases so that less can be more friendly to the environment. In addition, the excess of the engine with fuel injection type is more easily turned on at the moment not been used, and not affected at temperatures in the environment.

1. EFI System Working Principle
The term fuel injection system (EFI) can be described as a distributed system using a fuel pump at a certain pressure to mix with the incoming air into the engine. On EFI system with a gasoline engine, in general, fuel injection process occurs at the end of the intake manifold / manifold before the inlet valve in. (valve / spigot entry). At the inlet valve is open, is the suction stroke, the incoming air into the engine is mixed with fuel. Ideally, EFI systems must be able to supply some fuel that is sprayed in order to mix with air in a ratio appropriate to mix spin conditions and engine load, engine temperature conditions and atmospheric temperature at the time. The system must be able to supply the amount of fuel varied, so that changes in engine operating conditions can be achieved with engine performance remains optimal.

2. Basic Construction EFI System
In general, construction EFI system can be divided into three sections / main systems, namely: a) fuel system (fuel system), b) electronic control systems (electronic control system), and c) induction system / influent (water induction system ). These three main systems will be discussed individually below. The number of components found in different bias EFI system on each type of bike engines. The more complete EFI system components are used, of course EFI system will work better
so could result in engine performance is more optimal as well. With more complete components EFI systems, then the necessary correction settings to set the ratio of fuel and air in accordance with the engine working conditions will be more perfect. The figure below shows an example of the circuit scheme of Yamaha EFI system GTS1000 and placement of components on the EFI system Honda Supra X 125.

Picture 1. Schematic circuit GTS1000 Yamaha EFI system

Description number in the image:
1. Fuel rail / delivery pipe
2. Pressure regulator
3. Injector
4. Air box
5. Water temperature sensor
6. Throttle body butterfly
7. Fast idle system
8. Throttle position sensor
9. Engine coolant temperature sensor
10. Crankshaft position sensor
11. Camshaft position sensor
12. Oxygen (lambda) sensor
13. Catalytic converter
14. Intake air pressure sensor
15. ECU (Electronic control unit)
16. Ignition coil
17. Atmospheric Pressure Sensor

HOW WORK OF FOUR STROKE ENGINE

HOW WORK OF FOUR STROKE ENGINE

Suction Stroke
Process:
1. Intake valve open, exhaust valve is closed
2. Piston moves from TDC to BDC
When the piston moves down, pressure combustion become empty (vacuum). Differences in air pressure outside the high pressure with the empty, causing the air flow and will be mixed with gas. Further gas inflow through the valve flow into the open space in
cylinder.

Compression Stroke
Process:
1. Intake valve and exhaust valve is closed
2. Piston moves from BDC to TDC
After filling, the piston has reached BDC back move towards TDC, this room over the piston, so that the mixture of air-fuel to be solid, pressure and temperature rise. Pressure increased approximately threefold. Few degrees before the piston reaches TDC going sprinkling spark plug from the power to burn a mixture of air-fuel. When the piston moves upwards, the valve is closed and the inflow at the same time dispose of the valve is also closed. Mixed burning room until compress TDC, so with so quickly and easily start a burn.

Explosion Stroke
Process:
1. Intake valve and exhaust is closed
2. Piston moves from BDC to TDC
Mix burnt very quickly, the process of burning the gas mixture expands and exploted, energy and heat generated by fuel combustion in space to cause pressure and pressure all the way combustion piston pushing down (BDC), next play the crankshaft through the connecting rod

Exhaust Stroke
Process:
1. Intake valve is close
2. Exhaust valve is open
3. Piston moves from BDC to TDC
Before the piston moves down to the BDC, the valve opens and spending the rest of the combustion gas flow out. When the piston starts rising from the BDC, piston pushing the rest of the combustion gas that is still left out through the waste valve
channel and dispose on the air. Before piston starts to come down from TDC exhaust valve is closed and the mixture starts flowing into the cylinder.

HOW TO TWO STROKE ENGINE WORK

HOW TO TWO STROKE ENGINE WORK

Step Suction And Compression
1. The first half lap, or 180o
2. Piston moves from BDC to TDC

Under the piston
When the piston moves upwards towards space TDC will crank up and make space vacuum. Intake hole open. With This difference in pressure, the outside air can flow and mixed with fuel in the carburettor into the next room crank (called a step suction
or the crank space).

At The Top Of The Piston
Other income and hole-hole is closed by piston, so that the process of going step compression here. With the movement of the piston to the top urged the new gas that had been previously, create a temperature and pressure of gas increases. Some degrees before the piston reaches TDC plug will spattering on interest and start a fire to burn the mixture gas before (this step is called step compression)

Step Business And Discard
1. After a lap or two to 360o
2. Piston moves from BDC to TDC

At the top of the piston
When the piston reaches TDC a fresh gas mixture compress switched by spark plugs. Gas is burned cause an explosion that produces energy so that the piston pushing play crankshaft through the connecting rod when the piston moves down the BDC (the business). Few degrees after the piston moves to the hole BDC un open by the piston, gas-gas used to exit dispose of through the channel (step discard)

Under the piston
Some degree after the next channel un opened, then Rinse channel (channel transfer) start open by piston edge. When the piston to open the hole immediately transfer the disposal has been began. Gas new under the piston push, the mixture compress that is flowing through the channel Rinse the top of the room while helping fuel gas used to push out (this process is called flushing)

CRANKSHAFT

Crankshaft function is to convert the piston motion into movement of the play (machinery) and forward coupling force (moment of force) produced a motor to power the switching device to the wheel. Crankshaft bearings are generally held in a fixed glide on the crank. Crankshaft bearings are usually called the main bearings.
Type crankshaft used on motorcycle engines are:
1. Type of built-up used in small type motor has a cylinder number one or two
The burden of work on the crankshaft is:
- Load torque (torque)
- Load curved (bent)
- Load centrifugal
2. Type of "one piece", is used in large type motor that has a lot of cylinders.

Picture 1. Type crankshaft One Piece

For a single-cylinder motor in crankshaft axis (usually in front of the crank pen) is placed as a counter-balancing the weight of the crank cycle when the piston under pressure of work. But many of the motor cylinder, a pen attached to each other crankshaft balance. Weight of counter weight approximately equal to the weight of the piston rod at the crank plus the weight entirely. Thus the crankshaft can be balanced, so it can spin more evenly and the vibrations of the crank to be lost. With weight, This counter causes pressure on the bearings is reduced and evenly distributed.
Crankshaft and connecting rod is to change the translational motion of the piston to move around. These two parts are always suffering from stress and strain are very large. Because it must be made of special materials and the right size. Is at rest and the rotating crankshaft always equilibrium (balance). Hardened bearing surface and should be smooth to reduce wear.
Rotates with the crankshaft is supported by several major bearing fruit. The number of bearings depends on the number of cylinders. Four-cylinder motor has 3 bearings and six-cylinder motor has 4 main bearings. These bearings are made of steel mixed with some babbit or with aluminum. Connecting rod and crankshaft are made from cast iron. Installation of the connecting rod crankshaft bearings coated with wear.