1995 4.3 merc taking on water at the transom

[Deep Blue Water]

Help! I have a leak. On the water yesterday and the boat started filling up with water. I could see water coming in behind the eng. at the bottom of the outdrive on the starboard side. With the eng off water was shooting a streem stright up about 1" dia. 5-6" high.<br /><br />I pulled the outdrive off looking for a problem with the bellows, all of the bellows seem to be fine. I did find what looks like some kind of a oneway rubber coated flapper valve broke in half in the exhaust bellows. It was oval shape about 5" x 2.5 with holes for a piviot pin in the center.<br /><br />Anyone know where and what this valve is and where else to look for a leak?<br /><br />Also, not sure of the terminology but I am trying to get the piece off where the outdrive bolts to, the part the piviots up and down and side to side. with the trim indicater and limit switch off there is a 1/2" 12 point, fastener, is that a bolt and does that screw out.<br /><br />Thanks for any help and opinions

 

[waterone1@aol.com]

Re: 1995 4.3 merc taking on water at the transom

The rubber coated piece that you found is your exhaust flapper. This piece is supposed to be in the top of your Y pipe. Most likely the rest of this flapper is lodged in the bottom of the Y pipe and has worn a hole in it. That would be my first guess where the water is comming from. You need to look carefully inside the engine compartment and find where the water is entering from. The two 1/2 inch 12 point fasteners that are "under" the trim senders are bolts and will unscrew. You will have to get the propper tool to remove them, you could get it here www.mercstuff.com . Before I took anything else apart on the outside, I would concentrate on the inside first.

 

[Capt Ken]

Re: 1995 4.3 merc taking on water at the transom

Whoa, pump your brakes a minute. You're probably going in the wrong direction anyway. You are leaking in one of two places, either the shift bellows on the lower starboard side is leaking or the exhaust Y has a hole. Either way you don't need to disassemble the transom assembly. Check your shift bellows very carefully and if it ain't leaking there, throw the boat back into the water and use a flashlight and mirror to find the leak.

 

[achris]

Re: 1995 4.3 merc taking on water at the transom

If you found an exhaust flapper, you have another problem. All respect to Capt K, but I had this EXACT problem a few years ago. Same engine and year. Merc modified the flappers on the 96 model.<br /><br />The pins that the flapper moves on are stainless and wear through. When that happens the flapper drops into the exhaust 'Y' pipe and makes it's way to the outsside world. What you'll find is that one of them had lodged in the bend at the bottom and is vibrating and has worn a hole in the 'Y' pipe. That's where the water is leaking in. It happened to me 30 miles out to sea. I also thought it was the bellows, because when the boat is in the water you can see the water dripping down at the back of the engine, underneath.<br /><br />Sorry kid, it's leg off, engine out time.<br /><br />Chris...............

 

[Deep Blue Water]

Re: 1995 4.3 merc taking on water at the transom

Thanks for all the info.<br /><br />I found the hole in the exhaust pipe, The pin broke and the flapper was blown down into the exhaust pipe and knocked a hole in it. Pulled eng. welded pipe, installed new flappers after much grinding on the pipe openings to get them to fit, eng back in, outdrive will be on by Tuesday, shake down run on wednesday.<br /><br />thanks for all the info

 

[waterone1@aol.com]

Re: 1995 4.3 merc taking on water at the transom

Glad we could be of help. I'm a little worried about your comment about "much grinding on pipe openings to get new flappers to fit" ?? The new plastic flappers should fit without grinding (some clean-up...yes....grinding...no). The new plastic housing on the new flappers are a bit of a pain to get propperly installed....shouldn't require any grinding.

 

[Deep Blue Water]

Re: 1995 4.3 merc taking on water at the transom

waterone,<br /><br />I agree they should have fit with no problem, but I had to take off a lot of metal to get the flappers in and working smooth. Poor quality controll on the pipe.