Bob,
Yes, you need to loop the wire that goes from the ignition to the coil through the "transformer" on the rear of the tach. The "transformer" consists of one or two loops on the outside (through the plastic form and also the metal U) and many loops on the inside (part of te internal circuit). Yes, It matters somewhat which direction the wire loops, but I can't say which way, so try one direction and see if it works. But also note this key step I noted a few weeks ago to Steve:
Steve,
"An important thing to note is that you need, not just the plastic form to wrap the wire through, but you also need the U shaped piece of steel that fits around the plastic form. That U shaped (or staple shaped) piece of steel is a critical half of the steel core of the pulse transformer made up of the loop on the outside and the loops on the inside. If you have lost the U-shaped piece of steel you can probably make one from a piece of "tin can" - but be sure the can is steel (test itwith a magnet) and not aluminum. And when you assemble the plastic form and u shaped steel to the tach, be sure that both ends of the steel "U" make good contact with each end of the steel part on the tach. Otherwise you will not have a good transformer.
Many people have had problems with these metal U's,but I don't think most have realized that unless there is good contact at each end of the U there will be too small a pulse transferred to the tach to make good pulse counts."
I think SS also sells this U shaped steel piece and also the plastic part.
Tom H
