jrr

Hi everyone nice forum. I have a qustion regarding a 1978 yamaha dt 250 I just picked up. I bought this bike from a guy who says it needs a ignition coil and I found a coil for it but in searching i noticed this bike should have a cdi or should it not as there is not one on it but just a single wire harness going from the magneto up to where the coil mounts all lights and original harness are gone is it possible this model did not have a cdi or has it maybe been swithced any ideas, thanks im stumped