Tach & Power loss Intermittent

Yes, the tach signal is derived from the coil.

Not sure exactly the pattern of "Coil failure", but it's actually a fact that oil potted coils (like our OEM) really are not supposed to mount horizontal.
Ferrari ignored that!

So yes, I would clean and tighten all the various small wiring off the coil and condenser, and worst case I found MSDs round EPOXY potted coil is an almost exact dimensional size replacement, and is "Horizontal mounting OK"....

I guess a single distributor only has the one coil.....???

 

Even though you have a single distributor, the electrical portion is virtually still two completely independent ignition systems. Do you have points inside your distributor and two ordinary coils, or the "magnetic impulse" system with two "coils with electronic module control"?

 

You've got the conventional coils and distributor with points. Certainly possible to swap the coils to see if the trouble moves to the other side (i.e., same 1/2 power trouble, but the tach works) or not, but one of the points could also be the trouble (you could make point dwell measurements and/or visually/mechanically inspect them) or the cap/rotor/coil wire. Good Hunting!

 

If its similar to a mondial there is a multi pin plug mounted forward of the rear left wheel, behind the insert. They need a clean- tacho cuts in and out on me but no loss of power

 

This is a good clue, the connector itself but also the frame welded "bend over" fastening, which can, maybe, damage the conductors.

Those coils ARE vertical??
Can't see enough of the mounting but it looks like it...…..