massey tach question

[araz33]

I have a 431 with a tach problem

It works intermittently.

Sometimes holds at 500 before jumping into operation. Sometimes holds at zero before engaging. At one time made loud screech until engaging

Not wired to anything how does it get a signal-from where

 

[scott_vt]

Good Morning araz33,
Do you have a mechanical tach drive ? I just replaced my tach drive cable a few weeks ago, at 1700 hours mine let go !
I got a replacement from Mabie Brothers in Syracuse, Ny. It was about $75 as I recall, works fine now !