15hp 4 stroke merc water separator?

Discussion in 'Outboards' started by Mark C. Schreiter, Jul 15, 2021.

  1. Mark C. Schreiter
    Joined: Nov 2020
    Posts: 69
    Likes: 12, Points: 18
    Location: Tampa, Fl

    Mark C. Schreiter Junior Member

    so i live in Florida and i'm in the beginning/middle of building an all foam and fiberglass low sheer flats saltwater fishing boat around 15 feet when my dad calls me and says he wants to gift me his 16ft aluminum boat with the 15hp merc on it. Naturally I took him up on the offer. the boat is from 2005 and looks and runs like it just came off the showroom floor. he's way up in the midwest and it has never seen saltwater. I drove up to pick it up and brought it back to Tampa and instantly splashed it at my local ramp. I've never owned a boat and this is actually my first time as a captain. only took about 20 mins before i was pulled over by the water sherif, all went well he wanted to check my safety gear and luckily i sifted through the convoluted government and coast guard sites to determine what I needed and to my surprise I had it all.

    anyhow, the fuel tank is I believe around 6 gallons and i've only been using 93 octane on it, seems to be running great. there doesn't seem to be a water seperator and from research it seems to be split on whether I should put one on or just run it as is.

    Is the purpose of the separator to filter out the water from the fuel that you get from the actual pump or from condensation, humidity and potential water seeping in from the filler?

    I store it outside with a cover and its super humid here. it sat for a few days in storage and when I went to take it out the seats already had mold building up on them. it makes me think there is a ton of moisture building up and maybe it could be building up in the tank as well?

    so is it worth it to install one? do they had downsides, leaks or another point of failure that's not worth the risk?

    i have tow boat insurance and go out alone so I can learn the boat and the area and keep the stress down, (provided my wife approves the float plan).

    Sorry for the long winded post but I appreciate the advice

  2. Ike
    Joined: Apr 2006
    Posts: 2,651
    Likes: 454, Points: 83, Legacy Rep: 1669
    Location: Washington

    Ike Senior Member

    Not needed on a 6 gallon tank. If you had a large (like 100 gals or more) tank then maybe, but for a 15HP engine running off a portable tank it's not necessary.
    Yes the purpose of a water separator is to get the water out of the fuel. But the small tank isn't going to have enough water in the fuel to justify the cost. The O/B will just burn any off and keep right on running just fine.

    Better to go out with someone who knows the area at first and has some boating experience. Get a PLB, carry a cell phone (if you aren't going very far off shore). Better is a vhf marine radio. If you are going out alone it will keep you in touch with other people and the Coast Guard and Florida marine patrols. Most modern VHF radios have built in GPS and a emergency Mayday button. Well worth the money and your wife will appreciate it. For that matter, why not take her with you.
    bajansailor likes this.
  3. Mark C. Schreiter
    Joined: Nov 2020
    Posts: 69
    Likes: 12, Points: 18
    Location: Tampa, Fl

    Mark C. Schreiter Junior Member

    Good advice. after further research this seems to be the more common thought.

    the area I’ve been going out in is pretty popular and calm even on windy days as it’s mostly bays and estuaries. No plans to go off shore solo until I get vhf, better gps and a few other safety items. A buddy has taken me out in his boat in the same area several times so I think I’m decently familiar with it, however, going out after the recent hurricane showed me just how much the sea bed can change and they’ve been dredging all over and relocating sand to beaches and stuff.

    I’d love to bring my wife out and I will eventually but we’re just to different with that kind of stuff. She needs a bathroom and an agenda and a two hour max time on the water. I need enough gas to do whatever comes to mind. Lol.

    Thanks again for the advice.

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