Innovatize

See guys this generally happen in winters. In winters the temperature is low outside as-well-as inside the engine and it is not an optimum condition for combustion.So when we kick them we give initially force to the fly-wheel to perform first stroke so that combustion take place and we can get power stroke and then process get spontaneous! But due to low temperature the first combustion does not took place and the energy stored in fly-wheel(which is provided by us on kicking) is return back to us (by newton 3rd law of motion) and we get that back force or we say BACK.( BUT THIS PROCESS TOOK PLACE VERY QUICKLY



NOTE: OUR ONE KICK MAKE OUR FLY-WHEEL TO ROTATE MORE THAN ONE TIME !!       

WHAT TO DO WHEN OUR TWO-WHEELERS DOES NOT START ??

We generally push choke up so to provide rich mixture of fuel and when spark plug glow or provide spark the rich mixture burn quickly or very fast causing rise in temperature inside the engine and it completed our objective then we push choke down .

HOW DOES CHOKE WORKS ??

The choke is a separate throttle valve in the air intake, before the carburator,See when we generally put choke up the choke create vacuum which allows rich mixture of fuel(i.e more amount of oil than air) into
the cylinder and thus make easier to perform combustion in winters !

( FOR BETTER UNDERSTANDING SEE VIDEO ATTACHED )