KSW.... I'll PM you shorty.
SeaDooya... On the Sportster, a tach or speedo is able to be put in as an option, so the wires are behind the helm, (the multy guage is a little more work) but on an XP... you can tap into the yellow/black wire of the mag, and it will read the RPM's. One more thing... you need to add a 20k Ohm resistor to cut current going to the tach on that wire so you don't burn it out. (Get it at radioshack for about a $1)