Bad tachometer?

[CaneCutter79]

I have a 1979 Evinrude 85hp outboard. I bought a used OMC tachometer last year and it's worked fine until my last two outings. The tach needle is reading somewhere around 6,000rpm (stuck) and will not respond to the motor. Usually, when I turn the key on, the needle drops to "0". I have checked the wiring and it's getting both positive and ground connections. I don't recall if I checked the pulse wire but it should be working as well. If not, that would explain it but if the pulse wire is good, is there a chance the tachometer is busted?

I have a 31yr old boat and drilled a hole in the original dash. I hope this tach is not busted and if it is, I can find another one to replace it now that I have a 3" hole cored into the dash.

Thanks!

 

[Barnacle_Bill]

Re: Bad tachometer?

It certainly sounds like a bad tach since it's stuck on 6K.

 

[CaneCutter79]

Re: Bad tachometer?

It certainly sounds like a bad tach since it's stuck on 6K.

Considering my motor has never hit 6K, that's what I was suspecting. I'm not exactly sure when it happened but I was doing some work on the motor (replacing the head gaskets) and that's about the time the tach stopped working. I had a loose ground and the motor wouldn't start till I found the loose ground. Not sure how it ever hit 6K to start with unless an electrical surge hit it somehow.