Hi,
We have the Universal 5416 16 hp diesel engine on our Ericson 30+. For the past 12 years we have used a Racor R12 primary filter in addition to the normal secondary fuel filter on the engine. The Racor R12 is small, but works perfectly. We have never had a fuel problem, either water or dirt, though I am very careful about where I obtain fuel, always add Biobar to fight algae and some fuel conditioner like Stanadyne or Startron. I try to keep the fuel tank full to minimize condensation, especially in winter.
These Racor filters are not cheap, and the replacement filters inside are also not cheap, but they do work well. I replace the filter inside about every 2 years, or 400 engine hours.
Frank