Mystery Leak

AC2717 · 07-31-2014, 08:50 AM

I just purchased a 85 Monark modified v hull Jon boat (fishing set up) it has a 20 hp evinrude and. 40lb thrust foot controlled thruster

So here is my problem- keeping in mind that I replaced the drain plug already with a T type expandable rubber (and will be putting in a float switch for the bilge this weekend)

The boat is sitting on a mooring on the lake and after sitting during the night when I go out to it in the morning about 8am and switch the bilge it runs for about 4-5 seconds. When I then go out there about 7-8pm I switch the bilge on and it is running for about 30 seconds?

I am obviously leaking, previous owner never moored it as he day fished multiple lakes, not being swamped and have a new Basspro cover on it
I am off the belief that the rocking of the wakes during the day and causing pressure somewhere while attached to the mooring? While trolling or just drifting no water at all. I am thinking the rocking and back and forth tug on the mooring is creating sucking around the drain plug?
(my larger pleasure boat gets water in the same way but not to this extent or does it and it just does not seem it because of the size?

There are no dents in the hull, no cracks that I can see as I also filled it up with water and did not see anything before launching it. I have read about the drain plug tube being misshaped over time? Also there is marine epoxy on the stern from where something used to sit and that did not see to be leaking when filling the boat before launch. The forward live we'll is also dry so I do not believe it is coming there as I also have the drain tube straight up to prevent backwash from the drain
noticed also that my rear live well wont drain also not filling up unless pump turned on, and I think that is supposed to go into the bilge so I don't think its coming in through the live wells

I am thinking of putting some gasoline grade rubber line and clamping it around the drain tube and putting a ball value on it, and if it will fit, the drain plug on the outside to see if this is the problem, other than that there would have to be a crack somewhere
Help me out please

07-31-2014, 08:50 AM	#1
AC2717 Senior Member Join Date: Apr 2007 Location: Maynard, MA & Paugus Bay Posts: 2,522 Thanks: 747 Thanked 344 Times in 257 Posts	Mystery Leak I just purchased a 85 Monark modified v hull Jon boat (fishing set up) it has a 20 hp evinrude and. 40lb thrust foot controlled thruster So here is my problem- keeping in mind that I replaced the drain plug already with a T type expandable rubber (and will be putting in a float switch for the bilge this weekend) The boat is sitting on a mooring on the lake and after sitting during the night when I go out to it in the morning about 8am and switch the bilge it runs for about 4-5 seconds. When I then go out there about 7-8pm I switch the bilge on and it is running for about 30 seconds? I am obviously leaking, previous owner never moored it as he day fished multiple lakes, not being swamped and have a new Basspro cover on it I am off the belief that the rocking of the wakes during the day and causing pressure somewhere while attached to the mooring? While trolling or just drifting no water at all. I am thinking the rocking and back and forth tug on the mooring is creating sucking around the drain plug? (my larger pleasure boat gets water in the same way but not to this extent or does it and it just does not seem it because of the size? There are no dents in the hull, no cracks that I can see as I also filled it up with water and did not see anything before launching it. I have read about the drain plug tube being misshaped over time? Also there is marine epoxy on the stern from where something used to sit and that did not see to be leaking when filling the boat before launch. The forward live we'll is also dry so I do not believe it is coming there as I also have the drain tube straight up to prevent backwash from the drain noticed also that my rear live well wont drain also not filling up unless pump turned on, and I think that is supposed to go into the bilge so I don't think its coming in through the live wells I am thinking of putting some gasoline grade rubber line and clamping it around the drain tube and putting a ball value on it, and if it will fit, the drain plug on the outside to see if this is the problem, other than that there would have to be a crack somewhere Help me out please __________________ Capt. of the "No Worries"