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I have a 318 vista. The fuel valves are set to let both engines draw off of both tanks. However it seems to be only drawing from the right tank. I thought it was jus the gauges but I stopped for gas and put 50 gallons in the right and 10 in the left to fill it up. Any ideas. I tried turning off the right valve and the engines still ran from the left tank. Wondering why it would pull more from one then the other.

I was told by my dealer that this can be a common problem. The valves may have slightly different tolerances and the gas is drawn from the valve with the least amount of resistance even if it is very small difference. The side with the least amount of draw probably needs a new valve. I was told that it is an easy fix.

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07 Tiara Sovran 4300
07 338 Vista - SOLD

Is this a single or twin engine setup?

In our twin-engined 348 there are three valves. One for each tank and a 3rd one between them. Turn off the one in-between them. I had ours open for a while and noticed the uneven drain. Once I closed the in-between valve the problem stopped (obviously). Unless the engines are operating at significantly different RPMs the amount of fuel consumed should be pretty even.

Bear in mind that if you have a genset it probably pulls off only one tank (usually the one nearest to it). The fuel pickup for the genset is usually shorter than the one for the engine. This way you can't run the tank empty using the genset. Be sure to factor that in when planning trips and tracking fuel consumption.

As for valve opening sizes, that's bogus; at least for twin engine setups. It's not about the size of the opening, it's about how much fuel the throttle meters into the engine. You could have one valve half-open and the other open fully and, as long as the rate is sufficient to maintain RPMs, the consumption would be exactly the same. Think about it, unless you're cranking the engine to WOT (wide open throttle) it really doesn't matter if the valve openings are different. If a half-open valve can still deliver, say 8gph, but the fully opened one can deliver 20gph it wouldn't matter unless you actually needed more than 8gph. So I'd wonder what smoke that dealer's blowing...

But all this assumes there's a valve specifically dividing the flow between tanks. If it's not present then perhaps it'd be worth adding.

I'd also check any fuel filters that might be present. If the filters are before where the flow divides between tanks then a clogged one could certainly be a problem.

Thanks for the info. It is a 318 with twin 5.0 engines and a 3 valve system. I had all valves open so both engines should draw evenly from both tanks but was only pulling from starboard. Ran the Gen for only about 15 mins. When I close the center valve which allows each engine to run off its own tank the boat runs fine and both tanks drain evenly. Not sure what to make of it except like Barryboats says for some reason it is favoring the starboard tank.

I don't believe the center valve is intended to 'draw evenly' between the tanks. I can't imagine ever getting things balanced well enough to make it accurate. From what I've been told it's really only intended to let you pull from "the other tank" when something's wrong. As in, cut off flow from that tank because some idiot just put water or the wrong fuel into the fuel filler...

Since each tank has it's own shut off you can use the center valve to allow both engines to run off the other tank. I suppose if you ran the genset for "a long time" and drained one tank a lot more than the other you could also use this as a way to even them up.

Unless you're talking about more than a half tank it's not like there's going to be a big enough trim problem to make it worth this much effort. Gasoline is about 6 pounds per gallon. Just get someone to sit on the other side! Heh.

You really don't want to have the valve combining the tanks open except for when needed. Think about it. If you have contamonation in one tank and both engines have fuel coming in from that tank, you are liable to kill both. it's best practices to have the engines isolated to their individual tanks.

As to them drawing evenly, won't happen unless by just dumb lick. There are too many variables involved in the equation. Fuel line length, vent pressure differences, etc.

There will be one item you will want to change, that being the lingth of the genset pickup. Kohler's recommendation and the one FW foloweed is to have apickup tube for the genset configured to the half mark for the genset. It's a real pain. I changed out my tube so the genset cak use the second half of the starboard tank. We frequently run the tanks beloe half and usually on the way home, the genset would just stop.

I'd rather manage my fuel rather than have only half a starboard tank dictated to for genset use.

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Jvalich
http://www.badcock.com

'04 FW 288 Vista "Mental Floss"

Thank you all for the advice. I appreciate it.