Should I drain and refill my fuel tank before re launch?

[Crinan12]

Hi folks I've had various bother with my engine since I replaced my fuel tank last march.
The boat has been sitting in the yard since then and the fuel has been quite low most of the time
I suppose a lot of water will have accumulated in the tank over the space of a year?

My question is should I pump out all the old diesel from the tank and then fill it with fresh diesel, or do I just leave the old diesel in and fill it up, and let the CAV style water seperator do its thing?

Thanks

 

[VicS]

Drain off any water plus a little fuel

If there is evidence of diesel bug drain it all and clean the tank.

If there is no diesel bug top it up with fresh and add a dose of your favourite anti-bug treatment

 

[TernVI]

As Vic says, sample the bottom o f the tank and remove any water or dirty fuel.
If there is much water or crud, empty the tank into cans, clean the tank and let the fuel settle.
You can then filter most of the fuel back into the tank.
There should not be much water. If there is, check your deck filler really is waterproof.

Many tanks do not draw right from the bottom so water builds up over the years . I use a Pela oil extractor to 'hoover' the water and dirt, if there is any from the bottom of the tank.

If you keep the tank fairly clean, there is no need for fuel treatments.

 

[Crinan12]

Thanks guys
The tank is new so shouldn't be any dirt
But I'll pump out a bit from the bottom of the tank and see how it looks