The fuel gauge on the '99 Osprey I bought this spring has remained on Full ever since I topped it off for the first time in May. After a few trips, I topped off the 50 gallon tank again and it accepted 25 gallons, which means the gauge still reads Full with a half tank of gas. With the key/power on, when I remove the sending wire from the post in center of the sender access plate on top of the tank, the fuel gauge needle drops to Empty, then jumps back to Full when I touch it back to the post. So, the gauge is working and I figure I may need a new sending unit, right? The problem is, the five Phillips-head bolts that secure that access plate to the poly tank are very badly rusted and I know the slots will shear if I put any pressure on them with the screwdriver. I've sprayed foaming Wrench on them to help when it comes time to remove them. Any tips? Also, it appears Moeller Marine offers replacement sending units for 12-inch and 24-inch-deep tanks. I figured I'd measure my tank's depth once I got the access plate off, but in the meanwhile, if anyone knows which is the correct sender size for the stock 50 gallon tank in a 200 Osprey I would probably go ahead and buy one so that I have it on hand. Also, there are two (ground) wires leading from the side of the sending unit access. Why two? Any other advice on this project is very welcome!