Fuel tank questions

[Brian_M]

Hello, this is for the few of us that have saddle tanks, or knowledge of the tanks and plumbing:


1976 V20 w/ 165 *GM inline 6 and Mercruiser Drive

My fuel tanks seem to be getting excessive water in them, to the point of stalling the engine. When I remove the primary fuel filter (a Napa aftermarket installation) it is chock full of water...I drained the tank before memorial day and yesterday the boat shut down because of water in the fuel.

the questions:

Has anyone had similar problems, could this be just a big time condensation problem, or is there an class wide *weak link in the fuel system I'm not aware of

Should both tanks draw down at the same rate? it seems like the stbd tank is drawn down quicker

How efficent are the water absorbing additives in removing water from fuel, at $2.00 a gallon I hate to throw out the fuel

thanks in advance!

No MacoJoe, I'm not going to change over to a bracket and outboard (yet)

Brian

The vents, fuel fills have been checked and all seem to be OK, I did replace the O rings for the fuel caps as insurance..thank God for kicker motors!

[Crusher]

Brian M, MDR Gasoline Water Zorb, 16oz. treats 300gals about $8.oo dollars, I believe? Boaters World and most marine stores have it and other like products. Didn't say if you have a Racore Water Seperator? Clear bowl and valve at bottom lets you see and drain off some of the water, Don't leave the dock without one. Yamaha's hate water more than any other OB and have a hard time passing the water. Crusher

[Brian_M]

Crusher,

No racor, just a spin on filter to remove the junk from the fuel...I take it you have had good luck with the Racor, what size/model do you use, and where is it mounted in the fuel system...Thanks

[Crusher]

Brian M, Racores are sold as per your engine application. Mine is located in the motor well just slightly above and towards the front where the steering and battery cables come through. Look around marines most are located close to motor with easy access. Crusher

[reelapeelin]

Brian...my '74 had vent intakes BELOW the rub rail...got water in 'em when in ruff stuff all the time...moved vent intakes ABOVE rub rail an haven't had a drop of water in water seperator since.

Hope this solves your problem...it sure took care of mine...

[Seakindly]

RACOR is great. I believe USCG regs will require you to use the metal bowl if in enclosed space.

Ya gotta stop the water from gettin in. Doubt that much is condensation.

I would not use the fuel in my yamaha ob - it is a prima donna carba rata. ::)

Drain it and separate the water and use the good stuff in a lawn mower or something rugged, if you don't want to waste it.

[Brian_M]

Thanks for the insight! I bought a Racor yesterday with the steel bowl and will be draining the tanks this weekend. The vents look like they will be a beast to change around, but thats the only place the water could be coming in.

RAP, could you post a picture of where your vents are, mine are BELOW the rubrail, did you move your to the top of the deck, near the fill fitting??

[reelapeelin]

Brian...my vents are 12'' aft of the V-20 insignia under the side windshield, but you can put them any where along there...0 water in gas since I relocated vents...hope this works for you...you may have to get new hoses to get from tanks to new location of vents...it's not hard to relocate...for me the only bear was repairing holes in old location.

Good luck with it...

[macojoe]

I also have moved my vents to the same location!! I wasn't getting much water but I was leaking gas all over the trailer when trailering!!
You will need the elbow style vents to be able to fit them in there.

As for the tanks draning equaly they are not going to!! I have tryed everything and all the tips from everyone and it doesn't work.

One thing I have not tryed is to make all hoses the same length and that they have to both share the same vent!! This will cause the same perrsure in both tanks.
Will this work??? But I have 3 tanks now and have put a selctor switch in and when one runs out I switch to another.

[reelapeelin]

MJ...you're right about the elbow- style vents(two great minds runnin' in the same direction...sceeery, ain't it)...

Brian, I know you'll wanna top those tanks off, but don't...gas is cold when first pumped and WILL expand in the heat of the day and overflow your vents, wherever they are...

[reelapeelin]

Oh yeah, MJ...I don't think anything will drain multiple tanks simultaneously...wish it would...I got line from each tank to water seperator with single line to motor...in-line shut-off in both lines before water seperator...this is about as slick as I can get it...if anybody's got a better(proven) way, brother, I'd shore like to hear it...

Those in-line shut-offs are lever style, cause twistin' those little twisty things takes too dang long...

Happy motorin'

[reelapeelin]

Five more posts and this JUNIOR label goes away(I think)...then I'll be closer to GOD...in this case, is that a good thing or a bad thing????

[Seakindly]

OK ... here's a thought.

The tanks will drain equally when each one is hooked up to it's own motor.

Maybe the v20's founding fathers, in their infinite wisdom, came up with the saddle tank setup because the v20 was expected to be run with twin outboards, anyway.

I remember the OMC 135 was the beast, until mercury introduced the 150 in '74 or '75.

After all, the v20 was rated for what -- 275?? -- back then.

[macojoe]

I have a big selctor. has a 3 inch handle and you can chose tank 1,2,3,or off. Works great!! and just takes a second too change.

Also I left the old vents in place so I didn't have to repair the holes!! Call me lazy! ;D

[macojoe]

I am hoping when I hit 1000 post I am listed as extrem being!!

[Seakindly]

Of course, twins has nuthin to do with the i/o.

I really like the idea of twins on the v20. I would probably do that if I could on a v21. (ya can't).

And havin a separate tank for each motor would be swell. A fuel or fuel delivery problem in one, might not effect the other, and you still go home on plane. 8)

[reelapeelin]

I think the reason multiple tanks don't drain equally is different pressure in each tank...whichever tank starts out with the most gas(like goin' deeper in the water...deeper you go, the more pressure there is)...once that tank is flowing, it will tend to continue flowing(momentum), draining that tank first...even if you start out with EXACTLY same fuel in each tank, one will outdraw the other just cause it ain't a perfect world...line size(lenght), fitting sizes, intakes in tanks...SOMETHIN' gonna be different...

Am I thinkin' too much?...sometimes I think so...hurts my brain...