Single Cylinder Use
Most single cylinder four-stroke engines use the wasted spark system in order to capitalise on the simplicity and reliability of the flywheel magneto. These engines need a flywheel to run smoothly, and the heavy current-generating magnets help provide the momentum while delivering a zero-maintenance drive to the ignition system. Bolted directly on the end of the crankshaft this flywheel turns and operates at twice the speed that ignition is required.
As well as the build-weight and maintenance advantages of this system, there is a tuning advantage. Mounted directly on the end of the crankshaft all the stress that spark generation would otherwise place on the camshaft chain (or another special purpose half-speed drive) is avoided, while there is virtually none of the strain that necessarily degrades the ignition timing in systems relying on chains or gears.
Unlike the multi-cylinder systems noted above (which fire two plugs simultaneously from a double-ended coil) the coil in this system has only a single HT lead running to the single plug. The flywheel magneto provides other services in, for instance, small motorcycles, as it can easily be built to provide direct-current battery-charging power at almost no additional cost or weight.
Read more about this topic: Wasted Spark
Famous quotes containing the words single and/or cylinder:
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—Chinese proverb.
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