Topic: 1973 cb750 ignition

[sweeper]

I put a K6 motor in a K3 frame (and K3 wire harness). The ignition switch is a three position switch (off, start, start with lights). I replaced the old point ignition system with an electronic ignition and used power from the brakes wire to power the electronic ignition. It runs well in the second position (start). Unfortunately, when I switch to start with lights I loose ignition power and the engine shuts down but the lights work (except the brake light). I've been all through this bike and this is confounding. Any insights anyone may have that would be helpful would be greatly appreciated.

[bryanj]

Please get and read the hand book. It is NOT  off/start/start with lights It Is off/ start/ PARK WITH LIGHTS

[jaytee-nz]

Bryan is correct - virtually all old CB's have these three functions on the key switch.
You turn your lights on with the switch on the bars - not by moving the key to the third position.

[przjohn]

You may have what we term in the vintage circle as a "Rats Nest" for wiring. Anything else been done besides the engine swap? Maybe check your harness against a wiring diagram and see if something is not correct.

[jaytee-nz]

Err - it's not a wiring issue. The ignition switch was made in the factory that way !