CONTENTS

PAGE

CHAPTER I

TRACTOR PRINCIPLES

Comparison between tractors and automobiles—What is required for each—Advantage of understanding the mechanism—No standard tractor design—Principal parts of a tractor—Necessity for each 1

CHAPTER II

ENGINE PRINCIPLES

Power attained from heat—Combustible mixture—Principle of engine operation—Combustion space—Gas engine cycle—Dead strokes—Flywheel—Starting an engine—Inlet stroke—Compression stroke—Importance of compression—Ignition—Advance and retard of ignition—Power stroke—Exhaust stroke—Production of power—Vertical and horizontal engines—Firing order 9

CHAPTER III

ENGINE PARTS

Base—Bearings—Cylinders—Crankshaft—Piston—Connecting rod—Wrist pin—Piston rings—Valves—Cam—Valve mechanisms—Cooling system 30

CHAPTER IV

FUELS AND CARBURETION

Oxygen necessary for combustion—Forming a mixture—Rich and poor mixtures—Carbon—Preignition— Carbureter—Spray nozzle—Evaporation of fuels—Carbureter principles— Extra air inlet—Effect of heat on mixture—Loading—Strangler 52

CHAPTER V

CARBURETERS

Carbureter parts—Manifold—Action of carbureter—Float feed—Kerosene and gasoline—Descriptions of carbureters—Pump feed—Use of water in the mixture—Application of heat—Fuel pumps—Air cleaners—Governors 70

CHAPTER VI

IGNITION

Principle of ignition—Point of ignition—Preignition—Advance and retard—Parts of ignition system—Magnetism—Induction—Magneto—Action of armature—Armature windings—Circuit breaker—Circuit—Shuttle and inductor armatures—Sparking current—Grounded circuit— Magneto parts—Impulse starter 102

CHAPTER VII

BATTERY IGNITION SYSTEMS

Principle of spark coil—Windings—Timer—Atwater-Kent system—Vibrator—Spark plugs 131

CHAPTER VIII

TRANSMISSION

Transmission parts—Clutches—Necessity for change speed gear—High and low gear—Types of change speed gears—Necessity for differential—Principle of differential—Drives—Worm 143

CHAPTER IX

TRACTOR ARRANGEMENT

Tractor requirements—Tractor types—Engine position—Front axles—Spring supports 167

CHAPTER X

LUBRICATION

Importance of lubrication—Effect of oil—Kinds of oil—Effect of temperature on oil—Using the right kind of oil—Burning point—Viscosity—Lubrication charts—Oiling systems—Oil pumps—Mechanical oiler— Oil cup—Grease cup 175

CHAPTER XI

TRACTOR OPERATION

Using a new tractor—Breaking in—Daily inspection—Driving—Shifting gears—Driving on hills—Using the engine as a brake—Cold weather conditions—Starting in cold weather—Protection against freezing—Starting a tractor 201

CHAPTER XII

ENGINE MAINTENANCE

Fuel system and carbureter—Carbureter adjustment—Dirt in the fuel—Running on kerosene—Care—Magneto and ignition system—Care of magneto—Smoothing platinum points—Adjustment—Timing a magneto—Testing a magneto—Ignition trouble—Compression—Testing for compression leaks—Valve grinding—Valve timing—Carbon—Removing carbon 213

CHAPTER XIII

LOCATING TROUBLE

Engine will not start—Engine loses power—Engine stops—Engine misses—Engine starts; but stops—Engine overheats—Engine smokes 245

CHAPTER XIV

CAUSES OF TROUBLE

Troubles and their causes in tabular form 259

INDEX 261