Sorry Guys I like to tell stories on how i figure shit out haha
The Story:
So while ago I noticed my Tach was glitching (bouncing around and reading way higher than I was actually reving at) while Im driving and then began to just Peg out at 8K as soon as the engine starts.
I knew it was Tach related and not wiring cuz if i hit the dash it would Peg out if it was bouncing around.
So i pulled it out today to check it out and see if I could find anything oblivious wrong with it.
Well couldnt see anything that stood out so with the engine running and custer pluged in I was doing the "Wiggle Test" well when i was screwing in the Tach "Signal" screw I noticed that the Tach would jump.
Pulled out the Tach and inspected the Signal screw solder points to see that i looked like the Solder points were cracked.
The Fix:
Just took a Soldering Iron to the solder joints of the screw plate and bam she worked again! Dont Add Solder just "Re-Melt" Them
So if you got this issue try this before trying to source a "Newer" Tach.
Its Free and Easy
FYI: This was for a Kouki S14, Not sure if the Zenki is the same way, But just look for the Words "Sig" on the top side of the board