
What is the issue?
Tanks typically cannot vent displaced air as fast as modern pumps can fill fuel. The result is an excess of air builds up and releases back up the filler pipe through the infilling diesel. This typically causes diesel blowback splashing it about the boat.Why address this?
Diesel is virtually impossible to clear up. In our case the filler cap was in the cockpit sole and the smallest drop of diesel just dug in to the teak grating. Worse, it caused a diesel odour that lingers for months on end and we all know how that effects people who do not have well established sea-legs.How to address this?
Use a very long stemmed funnel to fill the fuel.Long stemmed funnels carry the incoming fuel deep down into the filler pipe. Provided there is clearance for air to release at the side of the long spout, the blowback will vent at the side and the infilling fuel is too deep below to be carried up and out of the filler point.

Photo: Courtesy of Mr Funnel
Making your funnel a 'filter funnel', that acts as a fuel filter and water separator such as available from Parker Racor or Mr Funnel, can also keep your diesel tank clear of damaging free water and contaminants that could spawn a diesel bug.
With thanks to:
Michael Harpur, Yacht Obsession.Add your review or comment:
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