Page:Motors and motor-driving (1902).djvu/197

Rh The chapter is divided into two parts, the first dealing with the 'Difficulties in starting,' and the second with 'Troubles on the road.'

A petrol engine will generally start most easily with all the cold-air inlets closed, the usual procedure being to shut these air-holes or taps, then let a little petrol into the carburator, shake the float needle (if there be one) or inject petrol into the induction valves or through the compression tap on top of the cylinder, if such exists; then, the ignition tubes being red-hot, or the electricity switched on and ignition retarded, a few turns of the engine should suffice to set it going; if, however, it will not start, the trouble must lie in one of the following sources:—1. Ignition; 2. Carburation; 3. Compression; or 4. Moving parts.

1. Ignition.—Having satisfied yourself that the ignition is in perfect order (see Chapter VIII.), the fault must be in one of the three sources remaining.

2. Carburation.—Let us first take the Carburation. There are many little things which may militate against a healthy explosive mixture reaching the cylinders, and we will first enumerate the principal causes in brief as follows:—

(a) Wrong proportions of air and gas.

(b) Carburator flooded.

(c) Carburator starved.

(d) Cold weather.

(e) Stale petrol.

(f) Handle not turned fast enough.

To deal with these more fully:—

(a) The mixture of hot air, cold air, and petrel vapour should be varied in every possible way—see that an excess of air is not being drawn in through a crack in a pipe or loose coupling.