Cleaning diesel fuel tank

[Ross G]

I have twin 200 litre fuel tanks connected via a balance pipe with shut off valves on each tank. When I refuel it seem to only need fuel in one tank whilst the other remains full. This leads me to think one tank has sediment or something preventing the fuel being used in one tank. Any ideas on how I could empty and unblock / clean out the fuel tank whilst on the water

 

[burgundyben]

Are you suure you don;t have the return lines running into both into one tank?

 

[Ross G]

I would expect both tanks to have the same amount of fuel if they are connected

 

[jrudge]

If there is a balance pipe filling one will fill both which may explain your issue.

The tanks are small so the lag on balancing will be an insignificant amount of fuel.

 

[Ross G]

There's two filler caps but tank doesn't ever need fuel

 

[jrudge]

if there is a balancing pipe that can keep up with the filling flow it won't ever need filling !

 

[Ross G]

When the fuel gauge is indicating say a quarter tank left I refuel the boat. I have never been able to fill the tank on the starboard side even if I try to fill it first

 

[jrudge]

If you tap it does it sound full or hollow?

If you say the make and model of the boat someone will know how the fuel system is set.

Many boats allow you to feed from any tank and return to any tank - so someone may have changed the valves.

If the tanks was not emptying then unless someone has messed with the valve set up the engine on that side simply wont run assuming you have 2 engines.

If you only have one engine then yes it would be possible it is blocked but given the pickup is not at the bottom usually but some inches up in the tank I would be surprised.

Turn off the good tank and see if the engine(s) stop.

Simpler to say the boat and someone will help.

 

[Ross G]

Thanks for all your replies. The boat is a starfisher 840wa with single 260 volvo penta d4 engine.
This is an extract from the manual.

The boat has two tanks with 200 L of capacity each located in engine room on the stern flanks. The tanks can be filled from both sides through two filler necks placed on the flank of the entry that gives access to the bathtub (WA)/ at the prow passage on the port at starboard side (CR and FLY) and identified with the term “Gas Oil”. Use always fuel of the best quality, to avoid impurities. As both tanks are connected, when one is being filled the other is being too. If the first tank is being filled very fast it may happen the second tank fills more slowly. To avoid this, wait a few minutes until the level is equal on both tanks and keep filling.

 

[jrudge]

I would turn off the apparently normal tank and check the engine stops. If yes then either e valve is dead or it is blocked. I would then blow through the line to clear it.

If that works great. Then pay someone to clean out the tank properly.

 

[Ross G]

Thanks for all your replies I will try that this weekend

 

[PCUK]

Close the suspect valve. disconnect the pipework and with a bucket handy slowly open the valve. That will tell you what is wrong.