OK here's the story on my former 03 ultra fuel gauge jump. Took to the stealer, they said they adjusted the tabs, ?????? Worked OK for a couple of days, then back to jumping or erratic indication. So being adventurous I took the sending unit out of the tank to diagnose. Its a real B**ch to get out, alot of twisting and contortions to prevent damage. Anyhow with voltmeter I was sweeping the float arm up and down and reading the voltage...erratic voltage...don't remember what it was (getting to old) Anyhow there is a circular push pin on the opposite side of the contact arm. I pushed it snug on the pivot arm and voila steady voltage readings thoughout the sweep range of the rheostat. Apparently over time the push pin, clip or whatever you call it works loose and allows the float pivot arm to have to much slack and so you don't get a snug contact. Sorry for the length of this but I talk much faster. That fixed my problem, sold the bike a couple of years later.