8
Small Gas Engines
Internal Thread Repair 63
Tapping New Threads 63
Threading with a Die 63
Washers 64
Pins 64
Cotter Pins 64
Clevis Pins 65
Dowel Pins 65
Straight Pins 65
Grooved Pins 65
Taper Pins 65
Rolled Pins 65
Retaining Rings 65
Keys 66
Adhesives and Sealants 66
Thread Adhesives 66
Sealants 67
Antiseize Compounds 67
Gaskets 68
Gasket Rules 68
C H A P T E R 4
Fundamentals of Electricity,
Magnetism, and Electronics
73
Introduction 73
Atoms and Electricity 73
Direct Current and Alternating Current 75
Electrical Units of Measurement 75
Ohm’s Law 76
Types of Electrical Circuits 76
Series Circuit 76
Parallel Circuit 77
Series-Parallel Circuit 77
Magnetism 78
Magnetic Fields 78
Theory of Permanent Magnets 78
Magnetic Attraction and Repulsion 79
Magnetism and Electricity 80
Electrical Components 81
Electrical Wire and Connectors 81
Switches 82
Solenoids 82
Relays 82
Transformers 82
Circuit Protection Devices 85
Electronics 86
Semiconductor Diodes 86
Transistors 87
Silicon Controlled Rectifiers 89
Electrical Test Equipment 89
Jumper Wires 89
Test Lights 90
Meters 90
S E C T I O N 2
Basics of Engine
C H A P T E R 5
Principles of Engine Operation, Two-
and Four-Stroke Engines
95
Principles of Engine Operation 95
Gasoline Must Be Atomized 95
Combustion Force Must Be Contained 96
Constructing an Elementary Engine 97
Simple Engine in Operation 98
Two- and Four-Stroke Engines 99
Four-Stroke Engine 99
Intake Stroke 99
Compression Stroke 100
Power Stroke 100
Exhaust Stroke 100
Valve Timing 101
Lubrication 101
Two-Stroke Engine 101
Variations in Design 102
Principles of Two-Stroke Operation 102
Scavenging and Tuning 105
Four-Stroke Engine vs. Two-Stroke Engine 105
C H A P T E R 6
Engine Components
109
Engine Components 109
Engine Block 109
S E C T I O N 2
Basics o f Engine OOperationerationp