bike konsi ha? is it 78cc chonda or 70cc honda? or some other beast ? i think it should be some 200cc two stroke
however most carb problems are solved if all jets etc are properly seated and torqued and there is no air leaks any where from tank to the carb etc..
have you tried using a definite amount of fuel to gauge its avg ? may be there would be some leak through which the petrol is evaporating during off time .. and over all you would be under the impresssion that that petrol is used by bike.
tell us mroe aboute your beast .