Responses to questions and more
Thanks folks for responding
I chose the Walbro because it was a marine rated diesel 12V pump with a separating screen filter on its intake for primary screening of junk (70 micron) prior to the RACOR. I think that this is a good match with the racor since the pressure and fuel flow match the racor 500fg pretty well.
I also chose the Walbro because of the low psi but seeing the rating on the RACOR of 15 psi says that I could probably put some more pressure to the system however I would limit it to 10% less flow than the Racor is rated for which is 60 gph. Your input regarding placement of hose in the tank is right on. My issue is that I bought the Whitby last summer and on my delivery home I noted that the port tank dropped quite a bit of black crud into the RACOR when turned on. I believe that the fuel tanks are baffled and there is no real clearance at the top of the tank (fiberglass with aluminum top) to get access. I figured that if I have 45 gallons in the tank and I am polishing at 40 gallons per hour I can run it for a few hours to turn over the tank a few time and try to clear it out. I always use a racor funnel when I add fuel and almost always add fuel from jerry cans so that I can limit the flow.
I know my starboard tank is clean and have added biocide, stabilizer, and cetane boost to all tanks. My keel tank I believe is a design flaw after 30 years and I will not be using it - might empty it and fill with antifreeze.
I am getting the boat ready for an extended cruise and thought that it would be a good idea to have polishing capability on the boat.
I will try to place the return hose to the bottom of the tank and do as much stirring as I can on the hard.
Thanks for all the input and please share any additional insight you might have