No announcement yet.

1985 Mako 235 Fuel Tank Filler Neckt

  • Filter
  • Time
  • Show
Clear All
new posts

  • 1985 Mako 235 Fuel Tank Filler Neckt

    After topping off my gas tank after a trip, I started smelling gas. The fill-up took less gas than I was thinking. The gas overflowed up the filler and vent. I still smelled gas when I got home. I saw gas sitting the sending unit. I took off the cover to access the filler hose to tank connection. I have only owned to boat for a year and this is the second time I have put gas in it. I have reached out to the previous owner(the original owner) to see if he has ever replaced the tank. The tank looks to be in very good condition, it looks to have a light coat of green zinc chromate primer on the top of the tank. The foam I can see between the floor and the top of the tank looks to be in good condition. I don't know if it is common practice to re-foam around a new tank. I noticed that gas was seeping out from under the hose where the filler neck attaches. I took 15 gallons of gas out so I could inspect the weld on the neck. After removing the gas, the seeping stopped. There are two hose clamps holding the fuel filler hose to the aluminum 90. It appears that the leak might be coming from the hose at the connection.

    The Main Question. Does anyone know if the 1985 Mako 235 has a one piece filler hose? I see that the filler tube goes from the gunwale filler port and sweeps down towards the floor. Someone told me that some Makos have an aluminum fitting under the floor - making it a two piece hose system. Also, if it is just a one piece system, has anyone successfully pulled a new hose into place without removing the entire coffin cover?

    I am cleaning up the area around the filler neck and I will add some gas back into the tank to try and see exactly where the leak is. The hoses were all dry as well as the foam forward of the filler neck on the tank. Hopefully it is just something with the hose. Hopefully the original owner calls be back and hopefully he tells me that it is not the original tank. I do not see any pitting or oxidation on the surface. I will update this post if he gets back to me.
    Thank you to all that answer.
    Last edited by Rayban305; 03-14-2020, 07:23 PM.
    1985 Mako 235

  • #2
    Update ----- I had someone dump some gas into the filler inlet. I watch the area around the fill hose / tank connection. Fuel instantly began leaking from the end of the hose. It almost seems like there are two hose layers. There are two hose clamps on the fuel fill line. I gave them a 1/4 turn each - no change. Does anyone know if there are two layers on the fuel hose? I am not sure how hard it would be to disconnect the hose from the 90 and clean the fitting and reinstall. I don't think cranking down on the hose clamps would do any good either.
    I appreciate any suggestions. I have added pictures. Thanks
    1985 Mako 235


    • #3
      I’m not sure if the 85 is the same as 81 but if it is, then there is only about a foot of rubber hose that connects to the elbow of the tank to the aluminum tube that goes up to the filler neck. Reach your hand it there and see if you can feel where the hose ends and the aluminum tube begins. You can also remove the cover by the fill cap, if it had the aluminum tube there will be a few inches of rubber hose connecting the fill to the tube. Additionally I’d bet that tank is original since the factory used that green zinc coating. Unfortunately your probably on borrowed time if the tank and aluminum filler are not already leaking. When I pulled my tank it hadn’t started leaking yet but the fill tube and vent tube were completely corroded through in several spots. Probably not what you want to hear but it’s the truth.
      Long Island, New York


      • Rayban305
        Rayban305 commented
        Editing a comment
        I agree. I knew the tank would soon be an issue. This is the first time I have smelled gas. When I reach down along the hose as far as I can, I only feel hose. Also I can see pretty far along the top pf the tank and I see nothing but hose. I am going to grab my dad's Milwaukee inspection camera and see if I can snake it along the hose. I will let you know how it goes. I am also thinking about removing the hose from the tank and try and see why it is leaking while filling.

    • #4
      So I'm in the process of replacing the entire fuel system in my 1990 171. You're filler inlet on the tank looks identical to mine, I imagine most tanks do. The hose itself has the exterior hose and the interior hose lining. If you can reach the hose to remove it from the fill inlet on the tank, electrical tape a new section of 10-12' of new fuel fill hose to it and push it while having someone pull it out of the fuel fill cap hole in the deck. I push/pulled mine and it snaked through pretty easily. Smaller boat, shorter path, but I'd bet it's a similar setup to what I literally just got done doing! I took the fuel fill neck & cap completely off the boat so I could pull the hose up and out of the boat. It's big and clunky and didn't want to bend 90* to come out of the access hatch in front of the fuel fill cap