® Stick coils


Why aren't high performance ignition coils a big deal any more on bikes, as they were fifty years ago. Is it because modern ignitions are so much better than before? No, not at all! In fact, they are weaker than before. High performance ignitions have fallen into disfavor, have in fact become unnecessary, in modern engines because of fuel injection. Fuel injection is so much more precise, deliberate and finely controlled that mongo ignition is no longer an advantage. Better fueling has eliminated the need for superlative ignition. Remember, opposites. This also explains how modern bikes can get by with the really low-powered ignitions they have now. You think the coil-over-plug ignition coil is stronger than the traditional high tension ignition coil? Not at all. It is far weaker.

The nature of combustion is such that air/fuel mixture and spark are interdependant. That is, each needs the other. The air/fuel mixture works best when the spark is vigorous, and the spark is most effective when the air/fuel mixture is potently metered. They each need each other. But what this really means is that if either is weak, the other has to compensate to maintain good combustion. If spark is weak, richer mixture is needed to make up for it. If mixture is weak, spark has to be stronger to compensate. They are inverse, or opposites. Thus fuel injection, whose major advantage is precise mixture, works well with the least powerful ignition.

Stick coils' reason for being is not power but control. They are the critical component in computer-controlled ignition systems that typically tailor ignition timing differently in each cylinder. It is foolish to think that fitting stick coils to a vintage engine is an advantage, as is proposed on some forums. It is a downgrade not an upgrade.


Last updated January 2025
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