I pulled my fuel tank on my Hunter 30 the other day to replace the board that sits under the tank. When I got the tank out, I noticed a sending unit for a gauge on it. My boat doesn't have a fuel gauge on it, but I would like to add one. a friend gave me a fuel gauge, but I'm not sure how to wire it up. There is only one terminal on the sending unit and five bolts holding it to the tank. I Would also like to add a clean out for the tank big enough to get my arm in to clean it out. Is there a cover that can be purchased or is this something that I'd have to have made? By the way, it's a plastic tank.