ZX CDI Mark2 -3 CDI conversion for SUZUKI GT 550 using existing points. The POINTS INTERFACE UNIT must be used with this conversion 

The CDI will draw only 12 watts (1 amp) from the battery as opposed to the 48 watts of the original system, and will allow the use of a brighter headlamp. The points will last almost indefinitely and ignition timing will stay set for very much longer. The inbuilt timing lights make initial setup a breeze.

1) Mount CDI to bike and disconnect battery. 

2) Disconnect 6 pin Molex style connector from the 3 ignition coils, and route the main harness end toward the CDI 

3) Route the CDI ORANGE, BLUE and DARK GREEN wires to the IGNITION COIL end of this connector and connect these to the PURPLE, BLACK/WHITE and BLACK. ( three ignition coil actives,  left, center and right) 

4)  Connect  three  BLACK wires to the three ORANGE wires in this same connector  (common ground), and ground these securely to the frame. 

5) Connect the BROWN CDI wire to one orange wire in the rerouted main harness connector as in step 2 

6) Connect the  BLACK CDI wire to a firm ground. 

7) Mount the Points Interface Unit in a suitable place where the three timing lights can be easily seen when setting up the timing. 

8) Connect the CDI YELLOW, PURPLE and LIGHT GREEN wires to the Points Interface Unit YELLOW, PURPLE and LIGHT GREEN . 

9) Connect the PIU BLACK wire to a firm ground 

10) Connect the PIU ORANGE,  BLUE and BROWN wires to the PURPLE, BLACK/WHITE and BLACK leads in the Molex style harness connector as in step 2 (left, center and right contact breakers) 

11) Connect the RED PIU wire to the ORANGE in the main  harness connector as in step 2 ( ignition 12 volt supply) 

The bike will now run.

Note:  The GREY wire is used to disable the ZX MK2 unit. This wire is taken to ground through the kill, or engine stop switch. This wire can also be used with a hidden switch as an anti theft, or used with an external rev limiting RPM counter. Current through this wire is approx 12 milliamps. If not used, this wire can be cut and ignored. IMPORTANT: If the ignition key is left on with the kill switch enabled, the CDI will be in standby mode and  still consuming battery power.
Click for Wiring Diagram