The tach on my 914/6 (conversion) has lost it's dampening. The tach needle is nice and steady as long as the engine rpm is constant. When the rpm changes quickly (such as when gear changes are made), the needle bounces. It takes a fews seconds to settle.
I remember reading a thread about adding a resistor to the circuitry to repair the problem.
Even though a 3.2 six has been installed in the teener the engine electronics and induction are still "old school" ... 40mm Weber carbs and points, condenser & CDI ignition. The tach is an early 70's 911 model with a 7,200 rpm redline.
Can anyone help me out/
Thanks
Eddie