fuel evaporation loss
Hai gassavers,
during some experiments on fuel economy, a strange thing happened. I was using a small bottle calibrated in CC ( I dont know its name ).while testing using the bottle mostly I fill upto 250 cc,drive till it is consumed fully and take note of the distance (In Kms). I am talking about motorcycle.mostly I shall get an average millage say 47 kmpl inside the city. but when I fill the fuel tank ( I measure and pour it inside every time and do not believe in the readings of the pumps at the fuel station) and drive I was always getting around 42 kmpl. I was so confused I had to check for leaks in the tank, tire pressure and all sort of other factors which where not the cause. Then I found out two things one cause was the weather, our hot summer, we do not have covered parking and usually park in the hot sun.
Next thing was the rubber insulator that isolates the inlet manifold and the carb. in my motorcycle there was a plastic flange gasket, As I had to put a 1/4 hose nipple for my experiments inbetween the carb and inlet manifold, I replaced the plastic flange gasket with aluminium flange extension with the hose nipple. and this arrangement was conducting the heat from the engine to the carb making the petrol in the carb evaporate. My carb shall hold about 50cc of petrol, so each time i stop the engine for a while 25 cc of petrol would be gone as vapour.if I stop about ten times for consuming one litre of petrol, i would lose about 250cc of petrol. i.e about 25% loss, the engine would have consumed only 75 %. Only then I foundout that modern motorcyles have rubber insulator inbetween the manifold and carbs which I had to follow to save some fuel.
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