2006 Mainship list to port

Just bought my first boat ! MS400. It lists to port. I'm sure it's the house bank of batteries. 4 golf cart bats. So to compensate I want to just fill the starboard h20 tank. When I fill it now it equalizes to the port tank. Any thoughts ?

Tom, I had a similar issue last year as one fuel tank was hiring more than other. Turns out I had a clogged fuel filter which I replaced and problem went away. Are your fuel levels even? Was there any aftermarket add one?

Btw we are based in Warwick.

tommynee said:

Just bought my first boat ! MS400. It lists to port. I'm sure it's the house bank of batteries. 4 golf cart bats. So to compensate I want to just fill the starboard h20 tank. When I fill it now it equalizes to the port tank. Any thoughts ?

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If 4 golf cart batteries (= one 240lb. guy) on one side of a 40' boat produces a noticeable list, I'd suspect there is more weight somewhere.

Are there any additions that may cause this? Full size fridge, generator?

Welcome aboard. Congrats on your new boat.

I use 25# bags of reclaimed lead shot-gun shell lead to occasionally re-balance the boat. I place them in out-of-the-way cubbies where they cannot shift in any seaway. The fuel and water tanks must be full to ensure ballast accuracy. Or, one must be certain that their levels are both very close.

Congratulations on the new boat. The water tanks are connected so they should equalize. I have 2 8D batts on each side for house, engine and inverter.

Hey Lollygag. I think you're on to something. The more we cruise the worst it seems to be getting. I'll check those fuel filters. We're up in Pawtuxet cove. 1st year with a boat. Just dropped the hook at Godard. Narraganset bay is awesome.

Looks like it might be just one of the fuel tanks being used. I'll take a look this weekend. Thanks

Thanks Mike. While I have you. Is the port side outside cutesy light not working even though the bulbs are good ?

Ha, I live at the other end of Pawtucxet cove. PM me we can set up a meet at O'rourkes for some Irish nacho's. Narragansett Bay is fun to explore, lot of good anchorages and places to hang.

The only add on is the aft bow thruster. It is on the listing side. I think it's the fuel tank. I'll check it out this weekend.

Fuel transfer valve may also be closed/blocked on one tank. Check the fuel levels which should be a good indicator. This is how we diagnosed and fixed the problem

I had the same problem with my 2006 MS400 single engine with a stern thruster. The thruster motor prevented the port water tank discharge line to have a straight line to the T fitting coming off of the starboard tank. This caused the port tank to maintain a higher water level. Solution was to install a inline shutoff valve in the port tank discharge line allowing me to isolate the tank allowing more weight on the starboard side.

Thanks Rawlitwn

I'll take another look this weekend. When filling H2O in the starboard side the two tanks do equalize. I think I might add that shut off valve just to have the capability to equalize. I'll post after I take a look to see if the issue is the fuel tanks.

I found the curtesy light circuit to be configuration a bit strange. You have to turn on the breaker on the DC panel and the third switch down next to the refrigerator for the curtesy lights. Also the switch near the stairs leading to the staterooms controls the curtesy lights for the interior stairs only if the breaker and the switch near the refrigerator are closed. Hope that all makes sense.

Hello,

We have noticed our 2007 40 is now starting to list to port as well. We have a single Yanmar and both tank feed lines go to a Tee fitting and from there through the primary Racor and then on to the engine....

There is only one fuel quantity gauge.. so I am not sure if there is a way to isolate to determine if the fuel is not balancing or could it be water tanks??..(unless I do a direct ohm reading at the fuel quantity sensor?)

all suggestions and comments welcome....

Sometimes you need to take a look with a fresh eye to your boat.

Besides batteries there are some other things which weigh quite a bit. Where is your toolbox, how about the dinghy motor, the chain locker, is your genny centered? Where are your spare props, where is the waste tank, air conditioner compressor, refrigerator/freezer, spare cooler?

One problem with self leveling tanks is that once you have a tilt to one side all the fluid will end up on that side and compound the problem.

pete

Hi jefndeb

My 2006 does the same. I,ve ruled out the air release hoses and water tanks. I think Pete might be right.. if there is a slight list to begin with then when the full tanks deplete it will favor the listing side. I think it’s a design flaw. If the boat is level when both tanks are filled. It should stay level as they deplete even though the engine pulls from port and returns to port. It’s annoying. At this point I,m just keeping the tanks as full as possible.

As I have explained before about my initial frustration with my single engine Mainship's inflexible (dopey?) fuel system, you do not have to accept this ridiculous setup. One of the easier DIY projects on a diesel powered boat is messing about with the fuel system. Add a second Racor if you only have one; route return fuel to both tanks via a wye valve; and you will likely find, as I did, an unconnected fuel sender in the tank not being monitored by the console gauge which can be connected to that gauge using a selector switch. No reason after those corrections to a crap system to have a list due to uneven fuel distribution.

rgano said:

As I have explained before about my initial frustration with my single engine Mainship's inflexible (dopey?) fuel system, you do not have to accept this ridiculous setup. One of the easier DIY projects on a diesel powered boat is messing about with the fuel system. Add a second Racor if you only have one; route return fuel to both tanks via a wye valve; and you will likely find, as I did, an unconnected fuel sender in the tank not being monitored by the console gauge which can be connected to that gauge using a selector switch. No reason after those corrections to a crap system to have a list due to uneven fuel distribution.

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Agreed. These systems weren't done right the first time. I'm sure I've read ten threads here discussing the issue. My old 34 is very sensitive to athwarships weigh distribution, but I keep it level by drawing and returning from one tank and swap as required. There are lots of good reasons for having the ability to fully isolate the two tanks. This is only one of them.

Jeff F said:

Agreed. These systems weren't done right the first time. I'm sure I've read ten threads here discussing the issue. My old 34 is very sensitive to athwarships weigh distribution, but I keep it level by drawing and returning from one tank and swap as required. There are lots of good reasons for having the ability to fully isolate the two tanks. This is only one of them.

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One of our MS 30 Pilot II members has a leaking tank and needed to isolate it after draining so he can continue to use the boat for a bit. Without the ability to direct the return to either tank, you could be screwed if the wrong tank leaks.

tommynee said:

Just bought my first boat ! MS400. It lists to port. I'm sure it's the house bank of batteries. 4 golf cart bats. So to compensate I want to just fill the starboard h20 tank. When I fill it now it equalizes to the port tank. Any thoughts ?

Click to expand...

Our 400 2005 use to lists to starboard a lot!
I think it depends on more weight in kitchen and head to the starboard side, but also the prop ”work” trying to twist the hull underway, with the yanmar engine.
All fluid goes to the low side and makes it lists even more.

Changes that may correct your lists problem!
With a filterpump I move the fuel as needed at the same time it polishing the fuel ( it’s also a second filter to the engine, if needed).
With a valve between the water tanks I control the water, but going to ad an 2-ways pump for more control.
An y-pipe in the return line split the fuel between the tanks, but going to add a shift valve and, in my case, direct all returnfuel to the port tank (it was only connected to the starboard from start)
The leveling will be even easier to control when the small remaing jobs (above) has been done.

Hi Boan400

It's interesting your 2005 MS400 feeds and returns fuel to starboard while my 2006 does the opposite. Feed and return to port. I think both fuel and water wye valves are the answers to this annoying issue.

I have a 2004 400T w/ the single Yanmar. The fuel return goes to the port tank. The Yanmars send a relatively larger amount of fuel back to the tank. As a result, the port tank always has more fuel in it until the boat stops and the tanks can balance out. Thus the greater amount of list to port underway.

Skip
Tampa

sailorskip said:

I have a 2004 400T w/ the single Yanmar. The fuel return goes to the port tank. The Yanmars send a relatively larger amount of fuel back to the tank. As a result, the port tank always has more fuel in it until the boat stops and the tanks can balance out. Thus the greater amount of list to port underway.



Skip

Tampa

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Skip
Agree with you about the greater amount of return fuel that goes to just one of the tanks, underway has the biggest impact. Water goes to the same side and the boat lists even more.
But in my case, it will not balance out when the engine stops becuse the selenoid valves at each tank closes the fuel line.
In my boat a loudly buzzer goes on when the ignition switch open these valves.
I think a good idea is to split the return fuel between the tanks in a proper way when the engine is running.

I asked myself what we have done different in the last week or so?.... and I have turned the dingy 180 degrees as hoisted on the davits to allow more boarding room to the swim platform and so now the dingy motor is on the port side....I dismounted the dingy and as expected it does level out a little more so I will keep an eye on it..

The other thing we have done more of course this month is to run the genset more than usual, even while underway,.. however I see it draws from the port tank so...

thanks to all for comments....

sailorskip said:

I have a 2004 400T w/ the single Yanmar. The fuel return goes to the port tank. The Yanmars send a relatively larger amount of fuel back to the tank. As a result, the port tank always has more fuel in it until the boat stops and the tanks can balance out. Thus the greater amount of list to port underway.

Skip
Tampa

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Skip
Our 400T/2005 w. singel yanmar has solenoid valves wich closes as soon as the engine stops, why the low side will remain to be low side. BUT the water goes throu the open cross line and make the low side even lower!

boan400 said:

Skip
Our 400T/2005 w. single yanmar has solenoid valves which closes as soon as the engine stops, why the low side will remain to be low side. BUT the water goes through the open cross line and make the low side even lower!

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You have solenoid valves (as in plural) which close the tanks off? Really? This is a first for me. I know engines have shut-down solenoid valves which cut the fuel supply to the engine, but they do not affect the fuel supply valves at the tanks which are always manually operated valves. If they are left open, as is the normal procedure on a single engine boat, and the bottom connecting hose (sluice line) is open, the tanks will be free to shift fuel to one another as previously stated with some boats (mine included) developing a list until some positive manual action like shutting off the high side tank and drawing from the low side changes things.