Small Engine Mechanics Course

Lesson 1 • Shop Safety and Tool Identification

Establishes safe work practices, PPE requirements, and proper tool selection before hands-on work begins. Directly supports injury-free lab performance throughout the course.

Lesson 2 • The Two-Stroke Operating Cycle

Details port timing, crankcase compression, and simultaneous scavenging unique to two-stroke engines. Contrasts with four-stroke principles to reinforce both.

Lesson 3 • Major Engine Components Overview

Identifies and describes the function of each primary engine component. Provides the anatomical framework students reference throughout the course.

Lesson 4 • Engine Types and Applications

Covers two-stroke and four-stroke engine classifications and their common applications. Establishes the vocabulary and context for all subsequent technical content.

Lesson 1 • Work Orders and Service Records

Trains students to write accurate work orders, record parts used, and log labour time. Professional documentation supports warranty claims and repeat-customer service.

Lesson 2 • Reading Service Manuals and Schematics

Teaches navigation of manufacturer service manuals, torque specs, and wiring diagrams. Accurate manual use prevents misdiagnosis and incorrect reassembly.

Lesson 3 • Multimeter Use for Engine Circuits

Applies multimeter functions to measure voltage, resistance, and continuity in engine electrical circuits. Builds electrical diagnostic skills used in ignition and charging chapters.

Lesson 4 • Measurement and Precision Instruments

Covers use of micrometers, callipers, feeler gauges, and dial indicators. Precision measurement underpins every engine inspection and rebuild decision.

Lesson 1 • Fuel System Components and Flow

Maps the path of fuel from tank through filter, pump, and carburettor to the intake. Understanding flow sequence is essential for systematic fuel fault diagnosis.

Lesson 2 • Carburettor Theory and Circuit Operation

Explains float, main, idle, and choke circuits and how each controls mixture at different throttle positions. Circuit knowledge directs targeted cleaning and adjustment.

Lesson 3 • Carburettor Adjustment and Synchronisation

Covers idle speed, mixture screw, and high-speed needle adjustment procedures. Correct adjustment maximises power, fuel economy, and emissions compliance.

Lesson 4 • Carburettor Cleaning and Rebuild

Guides disassembly, ultrasonic or solvent cleaning, jet inspection, and reassembly with new gaskets and needle valves. Proper rebuild restores correct mixture delivery.

Lesson 1 • Ignition System Fundamentals

Explains how magnetic flux, primary and secondary coil windings, and the kill switch produce and interrupt high-voltage spark. Provides the theory base for all ignition diagnostics.

Lesson 2 • Electronic Ignition Module Diagnostics

Addresses solid-state module testing, trigger coil inspection, and module replacement on modern engines. Electronic systems require voltage and signal testing rather than mechanical adjustment.

Lesson 3 • Ignition Coil Testing and Replacement

Uses multimeter resistance tests and spark testers to evaluate coil output. Faulty coils cause intermittent or no-spark conditions that require systematic isolation.

Lesson 4 • Spark Plug Inspection and Service

Covers plug reading, gap setting, torque installation, and heat range selection. Spark plug condition is the fastest indicator of combustion and mixture quality.

Lesson 1 • Splash and Pressure Lubrication Systems

Compares dipper-splash systems in small engines with pressure-fed systems in larger units. Students trace oil paths and identify components prone to failure.

Lesson 2 • Air-Cooled System Inspection and Repair

Covers fin cleaning, shroud integrity, and governor-controlled cooling airflow. Blocked fins or missing shrouds cause thermal damage within minutes of operation.

Lesson 3 • Engine Oil Properties and Selection

Covers viscosity grades, API service classifications, and synthetic vs. conventional oil selection for small engines. Correct oil choice directly affects wear protection and engine life.

Lesson 4 • Overheating Diagnosis and Prevention

Applies a systematic approach to identify lean mixture, low oil, blocked cooling, or excessive load as overheating causes. Students correlate symptoms with root causes.

Lesson 1 • Exhaust System Cleaning and Replacement

Guides carbon removal from exhaust ports and mufflers, and muffler replacement when restricted. Restricted exhausts cause overheating and significant power loss.

Lesson 2 • Exhaust System Components and Function

Explains muffler, spark arrestor, and exhaust port function and their effect on backpressure and power. Correct backpressure is critical for two-stroke scavenging efficiency.

Lesson 3 • Air Filtration System Service

Covers foam, paper, and dual-element filter types, cleaning methods, and replacement intervals. A restricted air filter is the most common cause of rich running and power loss.

Lesson 1 • Engine Reassembly and Break-In

Applies correct torque sequences, sealant use, and ring gap orientation during reassembly. A proper break-in procedure seats rings and bearings for long service life.

Lesson 2 • Bottom-End Disassembly and Inspection

Guides crankshaft removal, bearing inspection, and connecting rod side-play measurement. Bottom-end wear causes vibration, oil consumption, and eventual seizure.

Lesson 3 • Pre-Disassembly Assessment and Planning

Establishes a systematic teardown plan based on compression, leak-down, and visual findings. Proper planning prevents unnecessary disassembly and part damage.

Lesson 4 • Top-End Disassembly and Inspection

Covers head removal, valve extraction, and cylinder bore measurement for wear and taper. Top-end findings determine whether a bore job or hone is required.

Lesson 1 • Charging System Testing and Service

Covers stator output testing, rectifier-regulator function, and battery charging verification. A faulty charging system drains batteries and disables electric start.

Lesson 2 • Recoil Starter Disassembly and Repair

Guides rope replacement, spring rewinding, and pawl inspection on recoil starters. A broken or weak recoil prevents engine starting and frustrates end users.

Lesson 3 • Wiring Harness and Safety Switch Service

Covers harness inspection, connector cleaning, and safety interlock switch testing. Faulty safety switches cause no-start conditions that are frequently misdiagnosed as ignition faults.

Lesson 4 • Mechanical Governor Operation and Adjustment

Explains flyweight, spool, and linkage interaction that maintains constant engine speed under load. Misadjusted governors cause surging, overspeeding, or hunting.