[Evinrude Boater]

My neighbor's boat has a tach that rotates backwards to about 4,000 rpm regardless of speed. It goes back to zero when idling too. I know it's under warranty but that means pulling it out of the water and trailering an hour, leaving it, etc., etc.

[NYBo]

Sounds like the tach is bad. Is it still under warranty?

[ifallsguy]

A tach can be changed out with the boat at the dock. But if under warranty, the dealer may want it in his shop.

[orbit]

Is it a faria guage? If so check out their website, They have lifetime warranty on the guages and can mail you a new one.