new systems are installed, or old motors without directions may be purchased, diagrams for wiring the various types of motors, as well as several systems of both battery and combined battery and magneto, are illustrated in Figs. 126 to 136. In wiring for a motor, whether for marine, stationary, Fig. 127.-Wiring Single-cylinder Jump-spark with Batteries and Magneto or vehicle use, the best materials only should be used. About 80 per cent of motor troubles are due to ignition, and a large proportion of these are due to poor or faulty wiring. Too much care cannot be taken to see that all materials are perfect, all joints well made, and that the wiring as a whole is as well done and as free from the chance of injury, breakage, or short-circuiting as possible. For primary wires in the jump-spark system, or for the wiring on a make-and-break engine, fairly light wire may be used, but this should be of good quality, well insulated, and of the multiple-strand kind. Singlestrand wire is very good, but in connection with a motor the constant vibration is liable to break, or partly break, the wire and as this is not visible through the insulation the trouble is often very difficult to locate, especially Fig. 128.-Wiring Two-cylinder Jump-spark with Batteries only as the two ends may rub together, causing intermittent or weak connections. Where staples are used to fasten wires to seats, rails, or any woodwork, they should be fibre- or leather-covered, or when these cannot be secured, a bit of rubber, leather, or even cloth may be placed between the wire and the staple. Two wires should never be confined under the same staple, for if the insulation becomes worn or broken, short-circuiting is almost sure to result. Have as few joints in a wire as Fig. 129.-Wiring Make-and-break with Batteries Fig. 130.-Wiring Make-and-break with Batteries and Magneto possible, and when making a joint have the strands bright and clean and after being twisted firmly together they should be soldered. Soldering is not absolutely necessary, but it is safer, and with the modern soldering compounds, which can be used with a match or small torch or lamp, it is very easy to solder all joints. Whether Fig. 131.-Wiring any Number of Cylinders with Master Vibrator the joint is soldered or not, it should be well wrapped with several layers of adhesive rubber tape. Secondary wire should be of the highest grade and where there is dampness or grease it should be led through a metallic or fibre tube or casing. Grease, water, and oil will in time destroy insulation and allow shortcircuiting, and therefore all wires should be as thoroughly protected as possible. In marine work it is a good plan to run the secondary wires through rubber tubing and in all cases the wiring should be kept as short as possible. Avoid confusion of wires and keep each group separate |