| A motorcycle is a two wheeled machine which is | | | | wards with the leg. But latest motorcycles have |
| propelled forward by a motor. This motor is generally | | | | incorporated the self start option. In such bikes the |
| an internal combustion engine which imparts the | | | | pistons are fired by a starter motor. |
| forward momentum to the machine. The principle of | | | | The older motorcycles had their current supplied by a |
| gyro motion dictates the essence of motorcycle | | | | magneto. Now however the latest bikes are replaced |
| movement forward where the Centripetal and | | | | by Capacitor Discharge Ignition. CDI systems provide |
| centrifugal forces balance each other while the bike is | | | | higher ignition current for starting making the bike |
| in motion. Both these forces complement each other | | | | easier to start. Kawasaki was the first to adapt this |
| and give stability to the bike in motion. A forward | | | | for motorcycles. |
| momentum (Mass x Velocity) is an essential | | | | Another variant of the bike motor is the diesel |
| component for stability of the motorcycle when in | | | | engine. Unlike in cars the diesel engine is not adapted |
| motion. This forward motion balances the centripetal | | | | for large scale motorcycle use. This is because the |
| and centrifugal forces. This forward movement is | | | | diesel engine has a lower efficiency and is also |
| achieved through the power supplied by the internal | | | | heavier than a corresponding petrol engine. Diesel |
| combustion motor or engine. The motorcycle engine | | | | engines are prone to greater vibration and are |
| may run on gasoline or diesel. But now electric power | | | | generally unsuitable for two wheelers. However a |
| for traction is another option that is available. | | | | limited variety of diesel powered bikes are in the |
| In almost all motorcycles the engine is located just | | | | market. |
| below the petrol tank. This position has the effect of | | | | Bikes with large displacement usually have |
| lowering the center of gravity of the bike and gives | | | | multi-cylinders. Such motorcycles may have 2, 4 or |
| the machine greater stability. The motorcycle is | | | | even 6 cylinders. There are many types of |
| propelled forward by the engine which supplies its | | | | multi-cylinder options available in the market. Cylinders |
| traction power through a steel chain that is | | | | of the bike motors may be positioned in vertical or |
| connected to the rear wheel. All motorcycles are rear | | | | twin cylinder configuration. They may also be |
| wheel driven. Power is transmitted from the rear | | | | positioned in line. Another development is the Wankel |
| wheel by means of this metal chain. | | | | engine made by Felix Wankel (1902 - 1988). Wankel |
| The motorcycle motor's construction is quite simple. | | | | engines generate greater power for the motorcycle. |
| It consists of a single or set of pistons that move in | | | | Bike motors can go up to six cylinders. Six cylinders |
| a chamber or a sleeve .The motion is generated by | | | | are fitted on the heaviest bikes and include bikes like |
| an electric spark. The electric spark ignites a gas and | | | | the Honda CBX and the Kawasaki KZ1300. |
| air mixture that releases gases that move the | | | | Liquid-cooled motorcycles engines are a further |
| pistons up and down in a cycle. The pistons when | | | | development. Such motorcycles engines have a |
| they move generate power to a mechanism that | | | | radiator like in a car. The radiator follows the principle |
| moves a connecting chain to the rear wheel. All | | | | of heat dissipation and keeps the engine cool by |
| motorcycles are rear driven. | | | | circulating water or a liquid coolant. Liquid cooled |
| The power that is generated by the motorcycle | | | | engines can however be fitted only on the larger |
| engine is through the movement of the piston. When | | | | bikes and are unsuitable for lower displacement bikes. |
| the pistons move they impart the power to the | | | | Liquid cooled bikes for a specific displacement |
| crank which in this case is the chain. The cycle of | | | | generate greater power than air cooled bike engines. |
| motion of the piston in the cylinder may follow a two | | | | They also last longer than an air cooled engine. |
| stroke or four strokes. Two stroke engines have a | | | | Air-cooled bikes are however much cheaper to buy |
| simpler construction and thus are easier to maintain. | | | | and maintain with simpler construction. |
| They also generate more operating power vis a vis | | | | However, 4 stroke engines have captured the |
| four stroke engines. But four stroke engines are | | | | commercial market. Four stroke engine bikes give a |
| more eco-friendly and give a smoother ride on the | | | | smoother ride on the road and also generate greater |
| road. Another advantage of 4 stroke engines is that | | | | power over broader spectrum of speed. But despite |
| they can have multiple cylinders. This in turn | | | | this two stroke engines are in great demand in the |
| translates to greater operating power. In two stroke | | | | developing countries, as cost is a big factor there. In |
| engines very second stroke is the power stroke | | | | the United States and Western Europe the two |
| while in the 4 stroke engines the power stroke is the | | | | stroke bike is now an oddity and motorcycle |
| 4th stroke. A stroke refers to a single movement of | | | | manufacturers mostly market four stroke bike |
| the piston. | | | | variants. |
| All motorcycle motors have a rated capacity. This | | | | Another variant of the motorcycle engine is the |
| capacity is related to the volume of the chamber in | | | | electric engine. These engines are still in the |
| which the piston operates. The capacity of these | | | | development stage and are presently only used to |
| motors may vary from 25 cc to 1500 cc. The | | | | power small scooters and mopeds. These electric |
| capacity of the pistons and chamber is directly | | | | motors mostly operate on lead acid batteries. |
| proportional to the output of power. This is also | | | | However a negative point against these batteries is |
| referred to as Brake horse power. | | | | that they take more than 4 hours to recharge. They |
| The bike motor is started by means of an electric | | | | also have limitations of speed and performance and |
| spark. This in turn ignites the gas air mixture in the | | | | unsuitable for heavier bikes. However some concept |
| chamber and sets the pistons into motion. This spark | | | | bikes using a lithium battery have been tested but |
| is generated by a dynamo. Earlier bikes were all kick | | | | they are far from commercial production stage due |
| start. The bike was started by pumping a lever down | | | | to the prohibitive cost involved. |