I also use an autometer tach, no needle jump at all. I may be wrong,but I thought when I call them they told me the vtx1800 has a 1/2 pulse. honda dealer couldn't even tell that.If you cant get any help search for the autometer site and call them, they do have the right parts.
03 1800C, Chrome wheels, Tach,MTC clutch,mustang 3 pc seat, progressive shocks, power commander-dyno tuned w/sideburner pipe,1300 FINAL DRIVE,HID light,Odessy dry cell battery, stainless cables.
It's what Florida's all about