I have an older nissan 70 hp (NS 70A) with spark only on one cylinder. My question is this, since I have no spark to
the lower plug, tested to the plug, could it be anything besides the C D module since fire comes from single unit?
If it's a compact Ignition Coil & CD unit, then the unit is the cause. If it were independent Ignition Coil and CD, IC could be the cause, will need to troubleshoot first.
Yes, it can be something else. You need the service manual and armed with that you can run the tests on the other ignition parts. However, there is a 99% probability that it will be the CD.
