In winter, the engine gets cold and it can't start easily. but why?
Because the outside air is very cold. when it enter the combustion chamber and mix with the fuel, It might not ignite the air-fuel mixture. petrol ignites after vapourisation, but cold air will create less vapourisation. so rich air-fuel mixture ratio required. more fuel with less air quantity. so here choke comes into operation.
Choke valve working
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| carburetor |
Choke is a mechanism of the carburetor. which is used to increase and decrease the flow of air inside the engine, but not the fuel. we can control the inflow of air via the help of choke. if the choke valve off, Air will not enter into the engine. means only fuel can enter(rich ratio), fuel in more quantity can ignite easily. and the engine starts.