Starfire ZX Mark2 -2 CDI fitting instructions for Yamaha RD400. The POINTS INTERFACE UNIT must be used with this conversion 

CDI conversion for YAMAHA RD400 using the existing points.

1) mount CDI to bike and disconnect battery. 

2) Disconnect the  resistor block and discard. (3 RED/WHITE wires) 

3) Disconnect the ORANGE and GREY wires from the 2 ignition coils, and route the main harness end toward the CDI 

4) Connect the CDI ORANGE and BLUE wires to  the ignition coils RED/WHITE positive terminals, one on each coil. (two ignition coil actives,  left, and right) 

5)  Connect  two  BLACK wires to the two ORANGE negative terminals on the coils  (common ground), and ground these securely to the frame. 

6) Connect the BROWN CDI wire to the RED/WHITE kill switch wire removed in step 2 (12 volt ignition) 

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

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

9) Connect the CDI YELLOW, and PURPLE wires to the Points Interface Unit YELLOW, and PURPLE . 

10) Connect the PIU BLACK wire to a firm ground 

11) Connect the PIU ORANGE and BLUE wires to the ORANGE and GREY wires in the harness removed in step 3 (left and right contact breakers) 

12) Connect the RED PIU wire to any BROWN wire in harness ( 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.
The CDI will draw only 12 watts (1 amp) from the battery as opposed to the 32 watts of the original system, allowing a more powerful headlight to be used.. 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.

Click for Wiring Diagram