Funny Tach

[Double Trouble]

Another new adventure what could cause a tach to be eratic my starboard engine runs fine what could cause the tach to jump around it will go from1000 to 2500 and back to 1500 then stay steady for awhile and start all over again.Could it be as simple as a bad tach or wiring. Thanks for any help.

[GoneFission]

Sounds like a loose wire - that's the easy fix.  

I could not tell the year and model of your motor, but it also could be a stator getting ready to go out, as some tachs read stator pulses - that would be the not-so-easy fix.   :(

Let's hope for a loose wire; fix it and you're done!  

See ya on the water!

[John Jones]

My Johnson Oceanrunner tach went nuts.  It quit charging at the same time.  The voltage regulator was bad.

[Double Trouble]

My engine is charging just fine so I will look into the loose wire theory thanks for your help.

[Fishhyren11]

I'm going to have to agree, this sounds like a voltage regulator that's going out....

Mine went out, and my tach is going nuts, I got a new one, but still don't know how I'm going to put this thing in.  

[Double Trouble]

Took the tach out today cleaned all the contacts with electronic spray turned the adjustment knob a couple of times and sprayed that put it back together and wala works fine,sprayed and cleaned the other tach as well as the rest of the gauges while I had the dash apart.If any body fools with that adjustment knob take note of original setting first.