Tach Question

[Shadowfax]

My tachometer has suddenly started to act funny. When I start the engine the tach goes up to about 3,000 RPM, even though I'm probably at like 1,500. It eventually calms down after a couple of minutes and begins to read true.

Any ideas on what might be causing this.

 

[Cory B]

Regulator?

Our tach does this occasionally as well. It started when I replaced the original alternator with a balmar alt & regulator. Originally the alt provided the data to the tach directly, but now it goes from the regulator to the tach. I figure its just an artifact of our Balmar external regulator, and maybe has something to do with how it gradually ramps up the alternator.

 

[Brian K]

I've noticed the same problem occasionally with my Ericson 32-200 which has the same engine as the later E-34's. I'm suspecting a bad ground someplace but any suggestions on what to check would be appreciated. Thanks!
Oh, haul out on Friday,,,, BUMMER!!

 

[Chris A.]

When we bought our 34, the PO said the tach had suddenly started reading high- about double. We have an Ample Power alternator w/ external regulator. For my setup, the calibration screw on the back of the tachometer was all that required adjustment- perhaps it vibrates out of position? I calibrated against an optical tachometer and it's right on now. FWIW.