Re: GM DIS Upgrade using HEI Modules

Posted by Pinhead on Jul 12, 2011; 4:00am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/GM-DIS-Upgrade-using-HEI-Modules-tp3158051p3161333.html

So booya on points but sounds like cdi is better. Might have to rob a dohc.

The ignition system on the DOHC bikes (and the CB650) isn't actually CDI, though that's what my Clymer and Haynes manuals calls it. It is actually a TCI ignition.

TCI is fundamentally and functionally similar to a points system; they're both based on the Kettering ignition.

Which means there is one simple way to differentiate between the two: If the coils are supplied battery voltage at all times while the engine is running, it is a TCI ignition. If, on the other hand, the coils are "pulsed" voltage from some type of high voltage source (ignition box, etc) than it is CDI.

But that's just terminology. You're right that the DOHC ignition is far ahead of points. And if you replace the factory components with HEI modules and Cav coils, it's in a league of it's own.