Engine base, 30 Engine; double opposed, 25 Engine; horizontal, 25 Engine; how power is delivered by, 21 Engine loses power, 249 Engine misses, 252 Engine overheats, 256 Engine; priming, 214 Engine; principle of, 9 Engine; purpose of, 6 Engine smokes, 258 Engine starts; but stops, 254 Engine stops, 251 Engine trouble; locating, 246 Engine; vertical, 25 Engine will not start, 246 Exhaust stroke, 20 Exhaust valve, 38 Expanding clutch, 145 Extra air inlet, 63 Firing order, 28 Float feed carburetor, 76 Force feed oiling system, 186 Frame; purpose of, 8 Freezing; to prevent, 209 Front axles; types of, 172 Fuel; dirt in the, 215 Fuel; straining the, 89 Gas engine cycle, 11 Gasket, 30 Gasoline mixture, 57 Governor, 94 Grease cup, 197 Grease; when used, 182 Grinding valves, 229 Grounded circuit or ground return, 125 Heat; action of, 9 Heat; effect on oil of, 177 Heat necessary in forming mixture, 58 Heating the carburetor, 70 Heating the mixture, 86 Horizontal engine, 25 Ignition point; changing the, 103 Ignition system; Atwater-Kent, 136 Ignition system; parts of, 105 Ignition; theory of, 17, 102 Impulse starter, 128 Induction and induced current, 106 Inductor magneto, 115 Inlet stroke, 14 Inlet valve, 38 Jack shaft, 165 Jaw clutch change speed gear, 156 K-W magneto action, 115 Kerosene mixture, 57 Leaks of compression; locating, 228 Lean mixture, 54 Loading, 67 Lubricating systems, 184 Lubrication chart; use of, 182 Lubrication; importance of, 175 Magnetism, 105 Magnet; poles of, 106 Magneto action; Bosch, 110 Magneto action; Dixie, 119 Magneto action; K-W, 115 Magneto distributor, 124 Magneto distributor; cleaning, 222 Magneto inductor, 115 Magneto; oiling a, 221 Magneto platinum points; care of, 221 Magneto safety spark gap, 127 Magneto spark; theory of, 105 Magneto; theory of Bosch, 110 Magneto timer or circuit breaker, 110 Magneto timing, 223 Magneto trouble; testing for, 224 Manifold, 70 Master gear drive, 165 Mechanical oiler, 192 Mixer, 57 Mixing chamber, 70 Mixture changes with engine speed, 62 Mixture; formation of, 53 Mixture; gasoline and kerosene, 57 Mixture; heating the, 86 Mixture; heat necessary to form, 58 Mixture; rich, 55 Mixture; theory of, 9 Mixture; thin, or lean, 54 Oil affected by heat, 177 Oil; burning point and viscosity, 182 Oil cup, 193 Oiler; mechanical, 192 Oiling chart; use of, 182 Oiling; importance of, 175 Oiling systems, 184 Oil pump, 188 Oil; varieties used on tractors, 179