Trawler Slightly Listing - And Fuel Tank Valve(s) Info Please

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Centerpoint

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Joined
Apr 4, 2018
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Location
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Hi- And again, thank you for any suggestions to this Trawler Newbie.

Re: 1990 Marine Trader Aft Cabin

I have a slight Starboard list- about four degrees.
I have two 350 Gal diesel tanks in the aft cabin, under the beds
I have no fuel gauge - to tell what's full or not
I have never yet added fuel- as she remains docked

I have read that this may be due to a fuel balance issue and that I may need to either open one valve or close one- to equalize them.

I have NO idea where these valves are- or what positions they (or it) should be in.

I have considered ordering some fuel for the Port tank, in case the prior owner only ran off of the Starboard tank before I bought her, but have also read that in doing-so, without adjusting the valve(s) first, I may be adding to the problem.

Any thoughts on this please?

Thank you so much.

Jonah
CenterPoint
 
Greetings,
Welcome aboard, in case I've missed you. Is there no way to measure the fuel in each of the tanks? Surely a dip stick or some such...
 
Hi Center,
My boat has a permanent list to port due to some idiot putting all the house batteries on one side. :banghead: All my tanks run side to side, so I can't balance the trim there. Short of adding lead bars, there is nothing that I can do so I am just going to live with it. No big deal.

Cheers, Bill
 
Welcome.
I wouldn't worry about a slight list for now. Learn the boat first and you will figure out along the way if the list is permanent or simply a loading issue.

Be Careful with valving as some engines return a lot of fuel and if you draw from one tank but return to another it is possible to overfill the return tank and can cause a spill.

I would not add much fuel to a new to me boat and try to use up all the old stuff first rather than mixing new with uncertain age fuel. learn how to change filters and keep extras on board.

Have fun.
 
Thanks RT Firefly-

There is a way to use a dip stick. Both tanks have super easy access under the matresses, each with a large circle plate, about the size of a car hub cap, that can be unbolted.

Was thinking of opening them but I assume they will have some gasket- and concerned that the gaskets will be old and dry- and do not want to risk causing another issue just yet- like cracking them and having diesel smells without having new gaskets at the ready- and no idea where to get my hands on them.
 
I wouldn't unbolt those tank access plates. There should be an easier way to know about how much fuel you have without taking your bed apart, unbolting a plate and replacing gaskets.


Have you looked for a sight gauge anywhere?
I also believe you need to get someone on the boat who can show you which fuel line goes where, return vs supply and also go thru the valves with you. You should be able to feed from either tank, return to either tank and possibly move fuel from one tank to another.


IMO--you need to know these valves and their location.
 
Agree with prior advice. It’s good to know the flow of your fuel system. For instance, mine only draws from one tank, and then there’s a separate valve to ship fuel from one to the other. Both have simple sight valves.
All things being equal, my boat tends to list to port, since that’s where all my batteries sit. I compensate for this by keeping my starboard fuel tank 20-30gal higher than the port tank. Balances out nicely.
 
If it is a new boat to you maybe the previous owner removed lots of heavy stuff, tools diving gear, even a Motorcycle? more from one side than the other. See what, if anything you can shift around. Do you know or can you find someone who has the same boat, maybe they know of the problem if it is one. If not lead ingots or water container are fairly easy to add. Good luck!
 
If you can get to the side of the tanks, in the engine room for example, try using an ir heat gun to detect differences in temperature. If the ambient air temperature in the engine room is warm (after running the engines, for example...) the fuel will most likely be a lower temperature than the air above in each tank. That measurement will give you a qualitative assessment of the fuel levels.

Also, look for a “cross-over hose”. You should have a valve at the bottom of each tank connected by a hose; mine is half-inch diameter. When those tank cross-over valves are open, the fuel level between the two tanks will equalize.

Good luck!
 
As others have said, this is probably not a fuel balance issue but a boat loading balance issue. I found that to be true in Great Laker, and solved it by adding a couple of plastic bags of sand in an open space behind the galley cabinets against the hull wall. The further from the boat center line, the more effective they are. Add one and give the boat time to settle, then add another until level is achieved.
 
Our 37-footer came with a list to port. We measured the tankage and weight of batteries and other equipment and experimented with various tank levels. Found that with full water and half fuel we were about 1500 lbs port-heavy. In the end we added 500 pounds of lead to the starboard side and she trimmed out nicely. Because the ingots were placed far outboard the lever arm from only 500 lbs was plenty.
 
For right now I would shuffle things around in the boat to help correct the list. Then I would spend some time learning the boat and you may find that the problem is as simple as low fuel in one tank.
 
If the previous owner is available, ask him for the valve locations and how he determined the amount of fuel onboard. IF the PO is not available, start doing an internet search the brand of boat. You might find a users' group and then all your problems are over.

Before you move the boat, you really must find the valves and the amount of fuel on board. Perchance, is a fuel polishing/transfer system on board?

Ah ha, took less than 5 minutes searching.

http://www.mtoa.net

All your problems are over, I think, I hope.

Maybe you can gleam information here.

http://www.trawlerforum.com/forums/s10/mtoa-marine-trader-owners-association-18001.html

Two for the price of one. I am such a wonderful person. (patting myself on the back)
 
Last edited:
Welcome

my 1989 MT had a similar issue I took several steps to resolve but he main one was to rearrange my batteries

Do you have some pics of your boat?
 
how do you know how much fuel is in either tank and if both tanks are the same size.
I would look at both tanks and if they look to be the same size , I would drop a string with a small fishing weight down the fuel filling hole out side in the deck. go slow lowering the string until the weight hits the botto.m then pull back out and measure
string where it is wet and pink . do both tanks . this should tell you which has the most fuel. then measure height of tanks this gives you and idea if your tanks are 1/4 or 1/2 full
 
4 degrees is a fairly significant list. I doubt this is a fuel issue. boats rarely trim perfectly, particularly once furniture, gear, and provisions are loaded. My boat had about a 4 degree list to port. All of the cabinets, stove, fridge and guest stateroom are on that side. Everything else is centerline. Once the fridge and cabinets are filled, the list is pronounced.

I put about 400lbs of lead ballast on the starboard side to even it out. A friend with a sister ship put in about 350 lbs, however, he has a third water tank somewhat to stbd, which we suspect was Mainships attempt to address the list in later models.
 
I also have a port list due to the batteries, and am going to add a little lead to balance it out.

I am a believer in getting ahead of problems, I would pull the access plates and install fittings that would allow me to dip the tanks by unscrewing the access ports and then re-seal the plates with fresh sealant.

If you don't trust the seal now, why wait for it to leak? I would get ahead of the issue and make it a seal with a known date of repair. It's always good to know when things got done "right" the last time it was done.
 
I also have a port list due to the batteries, and am going to add a little lead to balance it out.

I am a believer in getting ahead of problems, I would pull the access plates and install fittings that would allow me to dip the tanks by unscrewing the access ports and then re-seal the plates with fresh sealant.

If you don't trust the seal now, why wait for it to leak? I would get ahead of the issue and make it a seal with a known date of repair. It's always good to know when things got done "right" the last time it was done.

+1

We also had a slight list when we bought our boat. Corrected by relocating batteries and adjusting stowage.

Time to get into the details on your tankage and how to manage feed and return, cross connect, etc.
 
Hello Jonah,

A 4 degree list may or may not be significant depending on your boat design.
My boat will list that much just because one water tank is full and the other is half empty. Because they are mounted far the the centreline they have a big effect on list. For this reason, I use them to correct other imbalances in load.

I use water from the tank on the low side or top up the tank on the low side. Much easier to do at the dock, than playing with fuel levels.

Also - I suggest it would be worthwhile crawling around the guts of your boat, and following hoses and finding all your valves. Try to get an understanding of the boats plumbing. Get to know her intimate areas. She'll love you for it.
 

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