Fuel/Water separator system advise...pls

Discussion in 'Boats, Motors, Trailers and Towing Rigs Forum' started by Robert Snyder, Nov 4, 2019.

  1. Robert Snyder

    Robert Snyder Crew Member

    Looking for advice on a good gasoline/water separating system to service both F300 and 9.9 motors? I have seen single and double canister systems.... what micron is commonly used for outboards?
  2. fish brain

    fish brain Crew Member

    Attached Files:

  3. fish brain

    fish brain Crew Member

    Sorry I'm not sure why the link came up three times
  4. gungadin

    gungadin Well-Known Member

    Carburettor outboards (all but the smallest ones) can use a 21 micron filter
    Fuel injected and small outboards should use a 10 micron filter.
  5. Buckethead905

    Buckethead905 Well-Known Member

    10 micron Racor filters have been good for me. You can get the clear bowl that fits on the bottom which has a drain built in.
  6. Prfisher

    Prfisher Active Member

    I think the clear bottom is essential in a marine environment. Had a standard Sierra spin-on the first season & it drove me nuts, not being able to see the fuel. The kit wasn’t expensive & I have my peace of mind back.
  7. casper5280

    casper5280 Well-Known Member

    Clear bowls are for outboards only. Steel/aluminum bowls for inboard/outboards only. In case of fire you don't want a plastic bowl in your engine compartment.
    mbowers likes this.
  8. ab1752

    ab1752 Well-Known Member

    Ours is the typical Volvo Penta spin on aluminum style so every 50 or so hours I spin it off, dump the contents into a clear jar so I can see what's up and replace the filter as needed. I only purchase fuel from 2 locations, both well known in our area and there was quite a bit of guck in there when I pulled it off last weekend. Reminds me I have to watch it more closely as I skipped the mid summer inspection.
  9. sly_karma

    sly_karma Well-Known Member

    IMO don't have your kicker running from main tank. Separate tanks and filters in case fuel contamination or line issues takes out your main. I use a 3 gallon portable for the kicker and dump it into the main tank every so often, fill up again with fresh fuel.
    wildthing likes this.
  10. searun

    searun Well-Known Member

    I've been running racor for last 20 years on my guide boats with zero issues. You can as others pointed out run a secondary line for your kicker. Not sure I would worry much about fuel contamination. The filter and water separator will deal with most issues unless you have a serious water in fuel issue. These are so rare, that the risk of fire or spillage from a secondary portable tank is hardly worth the worry.
    Prfisher likes this.
  11. Rockfish

    Rockfish Well-Known Member

    The same set up as ours. One replaced below deck keel line large Al tank and two complete supply systems from the duel pickups through bronze fuel cut off valves, hoses, Racors (filters/water separators) for each fuel line etc. One for the main outboard and one for the kicker. Very reliable and problem free system.
    Last edited: Nov 12, 2019
  12. wolf

    wolf Well-Known Member

    Same with my boat always watch the bowls and REPLACE . don not empty it out and think ok good enough once the paper is contaminated with water the filter is toast filters are cheap engines are not ... go with a trusted and proven racor system do not cheap out on some things ....
    fshnfnatic likes this.
  13. mbowers

    mbowers Active Member

    My advice is to use some 1/2 to 3/4 in starboard as spacers when mounting the head unit. That way you can actually get your fingers around the filter when changing it. Stupid boat builder in my case mounted the head against a curved bulkhead and even cross threaded the filter. That was a bitch to remove.

    Also use straight fittings only as 90deg fittings add pressure loss you don't need to the fuel system especially with a big outboard.

    Use the proper thread sealant and don't use the crappy galvanized fittings that are probably included with the filter. Buy brass or stainless.

  14. Birdsnest

    Birdsnest Well-Known Member

    I have always used a raycor fuel filtering and water separation units however my bowl is not in plain view. In the case of a major water contamination event,( which has happed to me twice, one where I left the fuel cap off in rough seas and the other time new fuel vents I installed allowed water into the tank in rough sees, ) my water alarm in the motor went off. In one case it was too late. Main died. The fuel line were solid water. The kicker lasted about 7 mins then died even after drain the bowl.

    for this reason I moved my water alarm from the motor to the raycor which give far advanced notice ensuring no water get in the fuel lines.
    This is a mercury product available for about $300. Not sure if this would be available for other make and models.

    So glad a made this change to my fuel system especially doing tuna trips and all.
    mbowers likes this.

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