I have a 2002 conquest with the FD 620 Kawasaki V-twin, sounds simple. The plugs that are in it are NGKBPR4es. I got Champion RN14YC (405) for replacements because that's what I could find. Now comes the confusion. The manual says Kawasaki changed the heads on the FD620 after VIN.# CB17---( I'm guessing the last 6 or 7 characters in the VIN. #) and the new plugs will damage the heads because they are too long. Does anyone else have this conflict the? Cross reference tables say their a match however the Champions do appear to be a little longer.