Fifth. The float should be so arranged that it is adjustable with reference to the lever that it contacts with.
Sixth. A gauze strainer should be placed at the gasoline inlet, and it is also advisable to have a similar strainer above the mixing chamber, beyond the throttle.
Seventh. There should be no pockets at any point in the body to hold the gasoline which might condense.
Eighth. The body of the carbureter should be so constructed that every part is easily accessible, and draining means provided so that every particle of gasoline can be withdrawn.
Ninth. Means for heating it, in case of cold weather.
Size of the Carbureter.—The proper size of a carbureter for an engine has been the subject of considerable discussion and experimenting. If its passages are too large, difficulty will be experienced in starting the engine, because the pulling draft through the primary will not be sufficient to make a spray that will unite with the air.
A carbureter too large will only waste fuel, even after the engine has been cranked up so it will start.
If the carbureter is too small the engine will not develop its required output of power. While it might work satisfactorily at low speeds it would be entirely inefficient at high speeds.
Rule for Size of Carbureter.—In all cases the valve opening and cylinder capacity in the engine should determine this. The size of the opening of the carbureter outlet should be the same as that of the engine valve, which is also the case where the carbureter supplies a multi-cylinder, as there is only one valve open at the same time.