Leakage in Pressure-fed Burners.—In pressure-fed burners, trouble is sometimes caused by leakage in the system of pipes, allowing the pressure to fall, or by water getting into them which has condensed in the pressure tank. Caution.—Before attempting to put a match near a burner, great care should be taken to be assured that the burner tap has not been inadvertently left on, and the engine box flooded. Many a good car has been burnt this way.
Burners Jumping Out.—Generally caused by too much pressure of petrol. The taps controlling the petrol supply to burners should only be opened a very little way—usually a quarter turn is sufficient.
Sudden bumps in the road will also cause jumping out.
Burners may also blow out. A proper wind shield should be fitted in front of the burner cage.
Spare Parts.—In connection with tube ignition it is necessary always to carry—
Spare platinum tubes.
Spare asbestos washers.
Spare nuts for tubes.
Spare burners.
Spare wicks.
Prickers.
A special spanner for undoing the nuts by which the platinum tubes are screwed into the cylinder.
A spanner for detaching burners from the supply pipe.
A spanner for removing the nipples of burners.
ELECTRICAL IGNITION
The Importance of the Time of Ignition.—As we have explained above, the moment that maximum compression is reached the compressed gases are forced into the hot tube and become ignited. After each explosion a certain proportion of burned gas remains in the tube, and the rising piston causes
