Thank you DIYer. I made one more improvement by attaching with silicone caulk, a thin Plexiglas cover at the back of the display to protect the open circuit board from metal particles. Also, all the soldered connections are covered with heat shrink tubing to prevent electrical shorts. Installing the tachometer display and wiring took about an hour (before waiting for the silicone to harden) and was one of the easiest tool projects I have completed this year. Paul