Motorcycle Repair: 1979 DT175 YAMAHA, spark plug wire, dt175

Question
I have gotten this bike from a friend,it has been garage kept for ten years.I have replaced the coil,the pickup inside the magneto for coil voltage,and spark plug but still no spark.The only thing left is the CDI box.the wire going from the pickup to CDI has power,coming out of CDI is orange and it also has power,(enough to shock you).that orange wire is input to the coil,but nothing comes out of the secondary side.any suggestions? how can a CDI be bad if it is letting that much power come out?If you have some ohm specs for tha unit that would be great.or if there is a cross reference to a newer bike that uses the same kind of ignition id like to know.the dealers ive called have no answers.I you could lead me in the right direction i wouldnt feel like pushing it off a bridge.. Thanks...

Answer
Hi Mike.

As long as you have power from the CDI box to the coil, then the problem is between the input side of the coil and the spark plug.

The ignition coil could not have tested good if no spark is getting from the input to the spark plug, unless the spark plug wire is a removable component of the ignition coil.  If that is the case, then it is likely that the wire is bad.

If the ignition coil and ignition wire are one component, then the coil is likely to be bad.

Check that and let me know what you find.
Good luck and ride safe.
FALCON