View Full Version : Erratic tach

07-14-2013, 09:59 PM
Boat is a '98 Maristar with an LT1, 125 hours. Today the tach was somewhere around 50% too high for the first hour out. After that, it was fine. Did the same thing last year- sometimes accurate, other times way high. Any ideas what would cause this?

07-14-2013, 10:34 PM
dirty ground?