Tiny Tach for Recon
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Not exactly, Kman; most small 4-stroke engines today have a "wasted" spark pulse at the end of the exhaust stroke (as well as the "real" spark pulse at the end of the compression stroke); the pickup triggering the spark discharge senses EVERY revolution of the engine.
Generally, old-style four-stroke point-and-capacitor ignitions fire every other revolution as you say.
Diogenes
Generally, old-style four-stroke point-and-capacitor ignitions fire every other revolution as you say.
Diogenes
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Thank you, Kman, for accepting the information in the helpful spirit offered.
You are quite right in the concept a four-stroke engine REQUIRES only one spark every two revolutions; however, for simplicity of manufacture, the "extra" spark pulse appears with pickup-coil triggered CDI systems. Some say the extra spark pulse helps environmentally, controlling emissions by incinerating unburned gasses. Maybe so; however, I bet that effect is very minor.
Diogenes
You are quite right in the concept a four-stroke engine REQUIRES only one spark every two revolutions; however, for simplicity of manufacture, the "extra" spark pulse appears with pickup-coil triggered CDI systems. Some say the extra spark pulse helps environmentally, controlling emissions by incinerating unburned gasses. Maybe so; however, I bet that effect is very minor.
Diogenes