I've Searched this forum with no luck, Read my instructions and hooked up my tach to the designated CDI wiring, Still no working tach. I know my tach is good because I can easily hook up my stock ignition and when I go to the negative coil it works fine. Anyone have a solution that does not require me to buy the tach adapter.

i did a writeup on this...

how to get your STOCK tach to work with a CDI ignition box without an adpater....

thought process:
What wire from the dizzy gives the box the trigger signal? (mallory unilite is green/white/red right?)

i *think* the trigger wire is the greeb one off of the unilite (going from memory)...

guess what the green wire is? a signal to the box to fire! and you guessed it.. if you splice/tee into that connection to the box, your tach will work fine!

i got mine to work with the Tach signal off the box too (internal mods to tach) if you are intersted in that too.

its really that simple. you can tap into the trigger wire from the dizzy to the box, or you can buy a tach adapter and run it off the tach circuit of the box, or you can internally modify your tach (search tach mod written by AGRUMP)

Or, you can get a Autometer 5" monster tach for like $100.00 Fits great and looks good. (at least in my car it does)

MSD Tach Adapter #8920 did the trick, Easy install and the original tach is once again giving vitals. I guess deep searches and sorting through everyone else's findings really works, Thank you 914 club members!