Ignition systems - all you might want to know and a whole lot more

[saaz]

http://www.jetav8r.com/Vision/Ignition/CDI.html

I came across this.  It sets out how things work, which might help in diagnosing problems.  Mind you ignition problems on STs are usually just old plugs that need replacing.

[Biggles]

Wow!  A lot to absorb there, but all great info.
Very interesting conclusion- there is no such thing as a "tune-up" of modern ECU engines.  The only thing that can be altered is the spark plugs.  If the "engine"  (in our case "FI") light is out, then everything else is doing its job and can't be improved.

[Sabie]

Thanks Saaz, that's a great piece of info to keep for us folks who drive old cars like my MGB.

Cheers

[saaz]

I well remember having to play around with points, which were one of the first things I got rid of when after market ignition systems came along.  having three sets to adjust, quite often, on the Suzuki GT750 triple was a pain.

Some modern ECUs do actively 'learn' from all the sensor inputs, and adjust the tune (mainly to keep the engine within emissions parameters). My Holden 5.7 V8 has twin timing tables to allow for the use of 91 through higher octane fuels, with ignition timing and fueling changing automatically.  Knock sensors, like on the ST13, are a key part of this.  I don't know why bikes are so relatively basic in this regard, as it makes sense to me that you should be able to use all the grades of fuel available, with the engine adjusting itself accordingly.