I also have the saddle tanks in my V and the fuel gauges absolutely suck. I have changed my sending units twice since I owned the boat in three years. They do work great for a short time then it's the same damn story over again. I wondered if it is the Ethenol that raises havoc with the sending unit?
An old timer told me a simple trick,"stick it". So that's what I do now for my fuel gauge. I use a wooden 1/4" dowel that I marked with a permanent felt tip marker at all the different levels, full,three quarters,half and a quarter. I filled the saddle tank (20 gallon) to the top, and then slide the stick down inside the opening all the way to the bottom of tank. Pulled out the stick and located the wet spot and that was my full mark. Measured the stick from top where the full mark was and divided in half and quarters. It's actually fool proof and works great and more accurate then the crappy fuel gauges I think. For saddle type tanks it works but for belly type tanks impossible.
