how bikes are starting in gear like yamaha,cbz etc but low weight bikes not like splendor,passion not?

how many carburettors are used in v-engines?and in which bike or car it is used

Please tell why we cannot use diesel engine in bikes? It is the cheapest.

something is generated in my mind why we not using exaust air will leaving from automobile. we make a small turbine and placed it near to exhaust air leaving from...