1. Objectives: - Discuss the uses of small engines - Observe all safety precautions when working with small engines - Distinguish between two and four cycle engines - explain how a 4 cycle engine operates - Explain how a 2 cycle engine operates - Identify all the systems in a small engine - Explain how the different systems of a small engine work Fundamentals of Small Gas Engines

2. Terms to know Internal combustion engine External combustion engine Four cycle engine Piston Cylinder Crankshaft Block Valves Intake stroke Compression stroke Power stroke Exhaust stroke Flywheel Two-cycle engine Piston rings Carburator Venturi Camshaft Governor Magneto Primary circuit Secondary circuit

3. Safety precautions Wear safety glasses and leather shoes Keep your hands, feet and other body parts from all moving parts. Do not allow burning material near oil, solvents or gasoline Do not smoke near openings of gasoline tanks or containers Disconnect spark plug cable prior to making any adjustments on machines to prevent the possibility of accidental engine start up. Stop the engine and allow it to cool before refueling Handle gasoline outdoors whenever possible

4. Safety precautions Never disengage any of the safety equipment or devices on the engine or machine Keep all shields in place Do not operate engines or force equipment beyond the designed capacity Never start and run an engine inside a building where the ventilation is inadequate. Never use gasoline as a solvent or to clean engine parts Dispose of gasoline properly, by pouring it into an approved container. Never pour in onto the ground or down a drain.

5. Types of combustion engines http://www.animatedengines.com/otto.shtml

7. How does a 4 stroke engine work? http://auto.howstuffworks.com/engine1.htm http://www.5min.com/Video/Starting-an-Internal- Combustion-Engine-145338934 http://www.5min.com/Video/Starting-an-Internal- Combustion-Engine-145338934

8. 2 stroke engine

9. How do 2 stroke engines work? http://science.howstuffworks.com/transport/engines- equipment/two-stroke2.htm http://science.howstuffworks.com/transport/engines- equipment/two-stroke2.htm http://videos.howstuffworks.com/howstuffworks/200- how-diesel-two-stroke-engines-work-video.htm http://videos.howstuffworks.com/howstuffworks/200- how-diesel-two-stroke-engines-work-video.htm

10. Engine Systems Compression system Fuel system Ignition system Cooling system Lubrication system ACTIVITY! Break yourselves into groups of 2-3 Each group is responsible for 1 system in the engine. You need to either make a descriptive poster or power point describing your engine system. YOUR group will be RESPONSIBLE for TEACHING other groups about your SYSTEM.

11. QUIZ! 1. What is the purpose of oil in the engine? 2. What is the governor? 3. What is the difference between a 2 stroke and 4 stroke engine? 4. What are some common causes of compression loss? 5. What connects the piston to the crankshaft? 6. What are piston rings needed for?