Info Manual

Many small bikes of today and tomorrow are now using the DC-cdi technology, this is for reliability and mantaining good spark every now and then, but then at somehow and at somepoint, the system fails. How does it fails?

Firstly, we must understand how the system works from start to finish.

     We'll now get into the ignition system itself. The outline simple enough. You start inside the left engine side cover, where two

PICKUPS
     sit near the rotor and produce a pulse of electric current when the pistons near TDC (Top Dead Center) which is fed to the

DC-CDI BOX
     (Capacitive Discharge Ignition, variously called the "ignitor box", "brain box", etc.). This box has two basic functions. It adjusts the signal from the pickups based on engine speed to change the timing as needed, and a capacitor thats being charged by an internal HV generator in accordance with RPM switches an SCR dumping energy of the CAPACITOR to the primary winding of the

IGNITION COILS
     so that the secondary winding is "induced" to spit out a high voltage shot to the

SPARK PLUG WIRES and on to the

SPARK PLUG CAPS which in turn sends it to the

SPARK PLUGS
     where all this voltage (maybe somewhere between 10kv to 40kv-that's thousands of volts) has enough pressure to make a small current jump the air gap between the electrodes at the bottom of the plug, thereby making a spark. This spark ignites the fuel mixture which, at that point is sitting all around the plug tip in a compressed state, ready to go BANG.

     So that is basically what happens But things aren't quite this simple, and so we'll take each element and talk about it in more depth. We'll also note the problems we've run into, the tests that can be made, and the repairs/fixes we know about. Please understand I'm not a trained engineer just an electronics guy. My comments are based on what I've learned from reading, talking with people, and personal experience with the system.