Where oh Where is my water leak coming from?

[BLACKIE]

I was out yesterday and I noticed that I'm getting some water in the bilge. I checked all the lines in the engine compartment and cannot see anyplace where water is coming in. It became noticable because I had the boat in the water all day and was tying it up at a dock for a few hours at a time then going out for runs all day long. Everytime I went to go out I had to run the bilge pump. Only had to run it for 30 seconds or less but I had to do this every couple of hours. I don't think the boat would stay afloat overnight. It seems to be a slow leak and I suspect its somewhere in the outdrive. I had the water pump, gimble bearing, and u-joints replaced last fall. Since I haven't run the boat much this summer I didn't notice the leak until yesterday.

The boat is a 1990 18' classic with a OMC King Cobra drive and a BB Chevy motor. It used to be owned by RedDog.

Any ideas as to how to determine where the problem (leak) might be?

[mattyboy]

speedo tube???

[BLACKIE]

I looked at it and the tube pickup is mounted on the transom with a line going into a box outside on the transom then the line goes up the back of the transom above the water line before it enters the hull. It seems to me that it could be a source of water entering while underway, however the water seems to enter while the boat is at rest. Is there a hull opening down at the speedo tube mounting point?

[onesubdrvr]

I looked at it and the tube pickup is mounted on the transom with a line going into a box outside on the transom then the line goes up the back of the transom above the water line before it enters the hull. It seems to me that it could be a source of water entering while underway, however the water seems to enter while the boat is at rest. Is there a hull opening down at the speedo tube mounting point?
My U-Joint bellows were leaking slowly, of course, on plane, running, wouldn't leak any, only when sitting, even then, not very much. Also, don't know if you are running through hub / hull, but could be the block - off plate for the exhaust, or that flange either way.

Wayne

[BLACKIE]

I'm running thru-hulls but I forgot about the hub block off plate. I suspect that the plate or the bellows is where my problem lies. The hard part is you cannot see either of them because of the engine. Maybe a mirror on a extendable stick to be able to look behind and under the engine. Anyone got an idea?

[RickR]

Blackie
While I owned the boat, I had to replace the ujoint bellows, twice. Both times it looked like a stick had poked a hole in it.
Also she has so little freeboard, you tend to get water IN the bilge pump hose and through the hatch in rough conditions.

[MOP]

The bellows is not a biggie, but if the exhaust plate has gone bad you can put off pulling the engine to fix it or clean the exit tube in the gimble then tape it over about 3/4 of the way and shoot blow foam in. When it cures trim it off and paint it, that fix will last many years I have done it on quite a few boats.

Phil

[RPD]

I've had a similar problem several times and I think the problem is the bow eye.

[BLACKIE]

Wow, thanks for the input guys. RPD, I'm not sure what you mean by the bow-eye. I think you mean a light mounted below the freeboard line in the front point of the hull. My boat does not have one.

I'm thinking is is the bellows, it's probably about 3 or 4 years old now. I expect water in the bilge while running but this leakage is when the boat is at rest in the water. I have to pump out about 2 or 3 gallons every 2 or 3 hours. I would not think it could be corrosion on the blocking plate because the boat is always stored on the trailer.

If I find that it is the plate I will be in touch with you Phil for more info on using the foam to seal it. I'm going to change the bellow first though.

Thanks again guys. :smile:

[Sam]

I had a mystery leak myself for the past few years and just found the source last week. The sealant (caulk) around the drain flange had gotten hard and shrunk.............hmmmm sounds like a personal problem :eek: . Anyway I pulled the fitting out and re-sealed and no more water in the bildge. Might be worth a look if you haven't confirmed your leak source.

Sam

[BLACKIE]

Interesting Sam, I never thought of the drain fitting leaking. How would you get it out to reseal it?

[CHACHI]

The bilge drain on my 87 Minx was leaking between the o.d. of the brass tube and the hole in the transom. The rubber plug sealed the inside of the tube . The quick fix was a small bead of silicone on the outside flange of the brass tube. This worked for two years, but I finally changed to the blige drain with a 1/2" pipe plug, like the newer Donzi's. Ken

[RedDog]

Blackie - I always suspected water was coming in through the bilge pump thru-hull fitting via backflow. I meant to test this theory by plugging the fitting to see if that stopped it.

[RPD]

By "bow eye" I mean the U bolt or Eye bolt in the bow used to attach the trailer winch... maybe yours doesn't have one, but most trailerable boats do... the water in my boat was entering while not moving or at idle speed when a wave would hit the bow about a foot or so above the resting waterline... then when I accelerated it moved aft.... then when I stopped more would might come in.... but it depended on conditions and very inconsistent.... hard to find... anyway, I think that is it....