Small Engine Ignition Systems

1
Small EngineIgnition Systems
Ch 9
Chapter Objectives - Upon completion of this
chapter you should be able to

• Explain theory of operation of ignition systems.
• I.D. the components of an ignition system and
  understand the function of each.
• Perform ignition system installations and
  adjustments.
• Explain sparkplug identification and
  construction.
• Explain the differences between a Magneto
  Ignition System and a Battery Coil Ignition
  System.
• Troubleshoot common ignition system problems and
  perform common repairs.

2
Small EngineIgnition Systems
Ch 9
Battery Coil -VS- Magneto Ignition System
Battery Coil Ignition
Magneto Ignition
3
Small EngineIgnition Systems
Ch 9
Point gap effects spark timing and Voltage
Magnitude
Condenser Absorbs current flow to reduce point
arcing
4
Small EngineIgnition Systems
Ch 9
Electromagnetic Induction
The Coil is a Step up Transformer
5
Small EngineIgnition Systems
Ch 9
The primary function of an ignition system is
to Provide a properly timed spark in the
combustion chamber of the engine that will ignite
the air-fuel mixture from the carburetor.
Points open
6
Small EngineIgnition Systems
Ch 9
7
Small EngineIgnition Systems
Ch 9
Spark Plug ID
Ribs Prevent Flashover
8
Small EngineIgnition Systems
Ch 9
Gapping sparkplugs
Selecting proper plug reach
9
Small Power EquipmentCranking Systems
S
B
M