Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-25-2019, 12:23 PM   #1
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
Fuel tanks not ballanced

We just returned from a long weekend and I have noticed that my starboard fuel tank is showing half empty while the port is showing full. The starboard talk has always drained a bit faster but this is more pronounced and has caused a slight list.

Valves on both fuel lines are open and the switch is set to both so the flow should be somewhat even. I was told it could be a clogged fuel vent or bad filter which I will check out. Any one else have this issue? Thoughts on how to fix.

Thanks
__________________
Advertisement

Lollygag1 is offline   Reply With Quote
Old 06-25-2019, 01:04 PM   #2
Guru
 
Conrad's Avatar
 
City: Calgary
Country: Canada
Vessel Name: Blue Sky
Vessel Model: Nordic Tugs 42 Hull #001
Join Date: Oct 2007
Posts: 1,723
Assuming that you are using diesel, I would look at how your return lines are set up. I often balance our tanks by diverting the return to the low tank. Also assume that you don't have or aren't using a balancing line between the tanks.
__________________

__________________
Conrad
Berthed in
Campbell River BC
Conrad is offline   Reply With Quote
Old 06-25-2019, 01:24 PM   #3
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 4,155
Quote:
Originally Posted by Conrad View Post
Assuming that you are using diesel, I would look at how your return lines are set up. I often balance our tanks by diverting the return to the low tank. Also assume that you don't have or aren't using a balancing line between the tanks.
+1. Check that the returns arenít both going to one tank. If they are you may spill diesel out through the vent.
Comodave is online now   Reply With Quote
Old 06-25-2019, 02:01 PM   #4
Guru
 
Benthic2's Avatar
 
City: Boston Area
Country: United States
Join Date: Feb 2017
Posts: 1,444
Does the generator also pull from the lower tank ?
Benthic2 is offline   Reply With Quote
Old 06-25-2019, 02:20 PM   #5
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
The generator does pull from the low tank, but is have noticed this issue after going out for the day. Will check the return lines when I get down there on Friday. I can always just fill the low tank more often but want to avoid stops to fuel dock if possible.
Lollygag1 is offline   Reply With Quote
Old 06-25-2019, 02:36 PM   #6
Guru
 
dhays's Avatar
 
City: Gig Harbor
Country: United States
Vessel Name: Kinship
Vessel Model: North Pacific 43
Join Date: May 2015
Posts: 7,690
Quote:
Originally Posted by Lollygag1 View Post
We just returned from a long weekend and I have noticed that my starboard fuel tank is showing half empty while the port is showing full. The starboard talk has always drained a bit faster but this is more pronounced and has caused a slight list.

Valves on both fuel lines are open and the switch is set to both so the flow should be somewhat even. I was told it could be a clogged fuel vent or bad filter which I will check out. Any one else have this issue? Thoughts on how to fix.

Thanks

Disclaimer: I know less than nothing about all things mechanical.


I would see how the boat runs on just the Port tank. Can you make full power on just the port tank vs the starboard tank?
__________________
Regards,

Dave
SPOT page
dhays is offline   Reply With Quote
Old 06-25-2019, 03:38 PM   #7
Guru
 
Conrad's Avatar
 
City: Calgary
Country: Canada
Vessel Name: Blue Sky
Vessel Model: Nordic Tugs 42 Hull #001
Join Date: Oct 2007
Posts: 1,723
Another thought. If you are using your dash tank gauges, one or both may be faulty. I ran into this a while back and the cause and remedy was simple. When the gauges were calibrated by the builder, once the calibration was done they put a drop of glue on the adjustment screw to keep the calibration true. Over the years the glue came adrift and my starboard tank was reading quarter full when it was in fact empty.
Proper sight gauges rule if you can get them.
__________________
Conrad
Berthed in
Campbell River BC
Conrad is offline   Reply With Quote
Old 06-25-2019, 03:55 PM   #8
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
I am also planning to check the gauges but last time I topped the tanks the starboard one took 40% more fuel. In answer to the other question I will test running just the port tank this weekend.
Lollygag1 is offline   Reply With Quote
Old 06-25-2019, 05:10 PM   #9
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 4,609
Might be a plugged vent line as well.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 06-25-2019, 05:27 PM   #10
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
I am planning to have the vent line checked too. Thanks
Lollygag1 is offline   Reply With Quote
Old 06-25-2019, 05:48 PM   #11
Guru
 
OldDan1943's Avatar
 
City: Aventura FL
Country: USA
Vessel Name: Kinja
Vessel Model: American Tug 34 #116
Join Date: Oct 2017
Posts: 3,339
Check to see if the value between the 2 tanks is open.
__________________
I will update this as soon as I can think of something snappy.
OldDan1943 is offline   Reply With Quote
Old 06-25-2019, 06:24 PM   #12
TF Site Team
 
Pack Mule's Avatar
 
City: Paris,TN
Country: USA
Vessel Name: William
Vessel Model: Outer reef 32
Join Date: Jan 2013
Posts: 3,311
Quote:
Originally Posted by Comodave View Post
+1. Check that the returns arenít both going to one tank. If they are you may spill diesel out through the vent.
Yep check those returns. Before I completely understood all my five fuel tank systems , I completely emptied one tank and overfilled another with the return line.
__________________
Marty
Pack Mule is offline   Reply With Quote
Old 06-25-2019, 06:26 PM   #13
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
This is a fairly recent issue so don't think it is a valve issue.
Lollygag1 is offline   Reply With Quote
Old 06-26-2019, 01:25 AM   #14
Guru
 
catalinajack's Avatar
 
City: Edgewater, MD
Country: USA
Vessel Name: Catalina Jack
Vessel Model: Defever 44
Join Date: Nov 2011
Posts: 749
Quote:
Originally Posted by Lollygag1 View Post
We just returned from a long weekend and I have noticed that my starboard fuel tank is showing half empty while the port is showing full. The starboard talk has always drained a bit faster but this is more pronounced and has caused a slight list.

Valves on both fuel lines are open and the switch is set to both so the flow should be somewhat even. I was told it could be a clogged fuel vent or bad filter which I will check out. Any one else have this issue? Thoughts on how to fix.

Thanks
Had the same problem. It was a plugged vent line. Critters blocked the small exit holes. The problem was so acute that when I opened the deck fill there was a rush of air to relieve the vacuum in the tank on which the vent was plugged. Of course, much less fuel was being drawn from it.
catalinajack is offline   Reply With Quote
Old 06-26-2019, 08:59 AM   #15
Guru
 
MurrayM's Avatar
 
City: Kitimat, North Coast BC
Country: Canada
Vessel Name: Badger
Vessel Model: 30' Sundowner Tug
Join Date: Jul 2012
Posts: 4,609
Quote:
Originally Posted by catalinajack View Post
Had the same problem. It was a plugged vent line. Critters blocked the small exit holes. The problem was so acute that when I opened the deck fill there was a rush of air to relieve the vacuum in the tank on which the vent was plugged. Of course, much less fuel was being drawn from it.
Same thing happened to us. I was doing a lazarette check on a long run when I noticed the different levels in the tanks. Good thing I noticed, or we might have "run out of fuel" it the plugged line had not resolved itself by the time the other tanks emptied out.

I'd suggest checking the least complex theory and then work towards the most complex.
__________________
"The most interesting path between two points is not a straight line" Murray Minchin
MurrayM is offline   Reply With Quote
Old 06-28-2019, 07:55 PM   #16
Member
 
City: Cypress Landing Marina
Country: North Carolina
Vessel Name: BZ interlude
Vessel Model: MS390
Join Date: Mar 2019
Posts: 13
I had similar issue with my MS390. Since I have a single engine, my filters are installed closer to Starboard tank (with a long hose to port tank). this means that the pump will more likely pull from the starboard if there is small contaminant in the port hose. to solve my issue the easiest way, I closed the starboard valve (to force the pump to pull from port tank only ) then started the engine. it took few second then I have noticed some black crap in the bottom of my filter-1 that was in use. replaced the filter and run to boat on both tanks without any issue since. I do have my cross over line and both upper valves open all time.
Regards,
DrissZougari is offline   Reply With Quote
Old 07-01-2019, 01:01 PM   #17
Guru
 
HopCar's Avatar
 
City: Miami Florida
Vessel Name: Possum
Vessel Model: Ellis 28
Join Date: Aug 2011
Posts: 4,261
One more possibility. I once ran a tank dry while running on both. I looked at everything suggested above including changing my hoses. I even pulled the fuel pick up out of the tank to check if the screen at the bottom was plugged. No screen.

The problem took me about a year to find. I eventually pulled the pickup tube again and took a closer look. I discovered that the tube was threaded into the fitting, not soldered as I had assumed.

I unscrewed the tube and there was the screen, full of little black chunks.

I threw that damn screen as far as I could, pulled the one from the other tank and threw it too!

I want the dirt to be caught by my Racor, not somewhere in the bowels of the boat where it is a major job to get at it.
__________________
Parks Masterson
HopCar is offline   Reply With Quote
Old 07-01-2019, 01:55 PM   #18
Member
 
City: Florida
Country: United States
Join Date: Dec 2017
Posts: 22
We had that problem as well...where the boat naturally listed to one side and the fuel tanks did not return to the correct locations....Make sure your boat is nice and level and then open all the lines so that the fuel naturally settles in their tanks and adjust any counter balance weights to handle the rest. We typically run with all of our tanks open, bow to stern, port to starboard and let. We used lead weights to redistribute the balance as over the years, past owners made additions and subtractions to the boat which changed everything around. Nice and level now.
__________________
Rob
Crazymonkey is offline   Reply With Quote
Old 07-01-2019, 02:00 PM   #19
Senior Member
 
City: Warwick RI
Country: US
Vessel Name: Lollygag
Vessel Model: 34 Mainship Pilot Hardtop
Join Date: Aug 2016
Posts: 168
Thanks all.

Vent lines- clear
Gauges- working fine
Valves - open
Next step is replacing the port fuel filter. Hopefully done tomorrow while i am still working so i can pay the mechanic.
If that does not work we will have to check the lines and other messy work.

FYI- gave the mechanic a bottle of olive oil hand pressed by a friend in Italy as an incentive to make this a priority over my dock mates pre-holiday requests.
Lollygag1 is offline   Reply With Quote
Old 07-01-2019, 03:40 PM   #20
Guru
 
Brooksie's Avatar
 
City: Cape Cod, MA
Country: USA
Vessel Name: Island Seeker
Vessel Model: Willard 36 Sedan
Join Date: Oct 2007
Posts: 1,008
Quote:
Originally Posted by dhays View Post
Disclaimer: I know less than nothing about all things mechanical.


I would see how the boat runs on just the Port tank. Can you make full power on just the port tank vs the starboard tank?

The main takaway should be that if your valves, for some reason, are set to draw from one tank and return to the other, you are in danger of spilling fuel without knowing it. Better to use one tank at a time (draw & return) then switching to the other tank at predetermined intervals to keep things even.
__________________

Brooksie is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 12:13 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012