I purchased a Mercury X1000 Tachometer to install in my boat. The directions for setting the cylinders on the back are wrong. On the directions that I received with the tach it tells me to turn the marker to a number 1,2,3, or 4. In my case #3--Mercruiser V8. These numbers are not on the back of the tach. The numbers that I have are 109T, 121T, 139T, and 155T. So, you can probably tell how irate I was after pulling the dash apart, installing the tach and then finding this. No boat ride today! So, I am hoping for some help with this. I searched the web for 2 hours and came empty. If I can't get any help on here I will then turnto the Marina that sold it to me. Unfortunately they are closed today.