How does fuel selector switch work on Carver Riviera?

[MikeL77]

I have a 1987 Carver Riviera that has two 220 Crusader V8's and two 80 gallon fuel tanks. Each motor runs off a single fuel tank. I want to install a fuel selector switch in it. How does the stock fuel selector switches work that originally came with Rivieras, and were found under the front stairs? Do both motors run off only one tank at a time? Or?
Thanks!

[mjk1040]

Mike; I assume your tanks are mounted on the port and starboard sides respectively, that being said, pulling fuel from one tank or the other only would tend to make the boat list if one tank is low and the other tank is full still. Personally I see no need for a selector switch on the fuel tanks unless you had an auxiliary tank too. Our 1986 Mariner had this same set up and another 1986 Mariner in our marina had a fuel selector switch in it, but I never took a look at it to see how it was set up. I just assumed it was set up to just shut the fuel off. At one point while running new fuel lines I contemplated y-ing the two tanks together so the fuel usage would be equal in both tanks all the time. The OEM selector switch in our 1998 355 AC allows us to turn the fuel off, pull from the auxiliary tank or each engine to pull from its respective side fuel tank, unless your going to install an auxiliary tank why install a fuel selector switch? The only other possible scenario would be to install one if you were to have a fuel issue on one engine and needed to switch fuel supply to get back to port? In any case that's going to be a lot of plumbing of fuel lines. Maybe just a roll of extra fuel line, a tee or wye so you could tap the good fuel source to run both engines until you got back to port? MIKE

[Viper]

Usually fuel selector valves allow you to set each engine to the port or starboard or auxiliary tanks. Whether it's as simple as one valve per engine or needing to turn a combination of valves depends on the type of valves used such as 2, 3, or 4 way valves.

The benefits of being able to select from one tank or another are; being able to switch in the event there is a fuel delivery issue on one tank or the other, and if you spend a lot of time running your generator on the hook, you will have much less fuel in that tank vs the other. Switching both engines to the tank that the generator doesn't draw from offers the ability to bring that tank down to the same level as the lower tank by running both engines off the higher tank for a while.