Fuel lines

[rockycoastcruises]

I have a 1987 Ablin 27 Sport with an Isuzu 6BD1 engine. I am replacing the lines going from the tanks to the engine and back. What diameter hose is standard for this engine. I'm running into 3/8ths and 5/16ths. Are the feed and returns line the same size?

And while I'm at it I have an extra Racor filter that I'm going to use. I'm trying to decide between having two filters to switch between or using one filter to capture larger particles and the second for what the first one misses. Any experience or opinion on this?

And last consideration is that I have a choice of using a squeeze ball for priming (like on outboard engines) or an electric fuel pump. Any suggestion on which might serve me best? I'm using this to fill the racors after cleaning. Any experience or opinions on this one? There is already an electric fuel pump wired in by not being used so it either comes out or will be integrated into what I'm doing.

Thanks

[RobS]

Fuel line sizes are fine. Yes, it is 100% normal for the return to be smaller ID than the supply.

I'd set up the double Racor's in series as multi state using 30 & 10 micron elements.

The outboard squeeze bulb would be all you would need for your priming needs and give you better feel and control than an electric pump But could the electric pump get you home if your fuel pump failed? ...... that could be something to consider too.

[rockycoastcruises]

Rob, thanks for your suggestions. I like the idea of a two stage filter system. I was thinking about the same thing with the electric fuel pump. Since it's there I will most likely utilize it.

[Ambler27FC]

I installed one of those two-unit Racor filters after a couple of fuel issues - which always happened in bigger waves when the tank was being agitated. It is very comforting, but I found the real advantage was the meter measuring pressure across the fuel filter. With a meter, the second filter is not necessarily beneficial - you can always be in front of the issue.

I asked my engine manufacturer (not Isuzu) about the recommended filter. I had been using 10 micron, but they recommended 30. Said you would have too much pressure with an10 micron. Probably varies engine to engine.

Very happy with my electric pump to top off the filters, but have thought a bulb pump (simpler = better).