The bike motor is started by means of an electric spark. This in turn ignites the gas air mixture in the chamber and sets the pistons into motion. This spark is generated by a dynamo. Earlier bikes were all kick start. The bike was started by pumping a lever down wards with the leg. But latest motorcycles have incorporated the self start option. In such bikes the pistons are fired by a starter motor.
The older motorcycles had their current supplied by a magneto. Now however the latest bikes are replaced by Capacitor Discharge Ignition. CDI systems provide higher ignitioncurrent for starting making the bike easier to start. Kawasaki was the first to adapt this for motorcycles.
Another variant of the bike motor is the diesel engine. Unlike in cars the diesel engine is not adapted for large scale motorcycle use. This is because the diesel engine has a lower efficiency and is also heavier than a corresponding petrol engine. Diesel engines are prone to greater vibration and are generally unsuitable for two wheelers. However a limited variety of diesel powered bikes are in the market.
Bikes with large displacement usually have multi-cylinders. Such motorcycles may have 2, 4 or even 6 cylinders. There are many types of multi-cylinder options available in the market. Cylinders of the bike motors may be positioned in vertical or twin cylinder configuration. They may also be positioned in line. Another development is the Wankel engine made by Felix Wankel (1902 - 1988). Wankel engines generate greater power for the motorcycle. Bike motors can go up to six cylinders. Six cylinders are fitted on the heaviest bikes and include bikes like the Honda CBX and the Kawasaki KZ1300.
Liquid Cooled engines
Liquid-cooled motorcycles engines are a further development. Such motorcycles
However, 4 stroke engines have captured the commercial market. Four stroke engine bikes give a smoother ride on the road and also generate greater power over broader spectrum of speed. But despite this two stroke engines are in great demand in the developing countries, as cost is a big factor there. In the United States and Western Europe the two stroke bike is now an oddity and motorcycle manufacturers mostly market four stroke bike variants.
Another variant of the motorcycle engine is the electric engine. These engines are still in the development stage and are presently only used to power small scooters and mopeds. These electric motors mostly operate on lead acid batteries. However a negative point against these batteries is that they take more than 4 hours to recharge. They also have limitations of speed and performance and unsuitable for heavier bikes. However some concept bikes using a lithium battery have been tested but they are far from commercial production stage due to the prohibitive cost involved.