Leaky Mastercraft - Need Help

My 2001 209 sprung a leak last season. I am going to be brining into the garage for some winter projects, but the biggest one will be identifying the location of the leak. I am pretty confident that the leak only occurs when the boat is not moving, but it is difficult to tell. I imagine it is one of two things, either my packing is leaking or the rudder seal has deteriorated. My plan at this point, with some help from Grant, is to pull the flooring above the packing and set it out in the water to see if we can locate the leak.

Two questions for you......

If it is my packing, does anyone have experience either tightening the packing or replacing it? and which do you suggest?

If I need to replace it, I understand it needs to drip at a certain speed? Is it drips per second? minute? etc.

If it is my rudder seal, what is involved in replacing it?

The success of my 2006 season is in your hands, please help. Grant will kill me if I sink his Sound Illusions stereo install

How bad is the leak?

If you have a stuffing box then the first thing you should do is just tighten it a little bit. There will be a skinny jam nut that has to be backed off first, then the packing nut tightened down. The packing nut should turn easy, so if the jam nut was not too tight the cheap wrenches you can buy at the hardware store for doing drain work will usually do the job. You will need two, one to hold the packing nut and one for the jam nut.

This is a job best done in the water. Tighten it a quarter turn at a time until the leak slows down to a slow drip. You want a slow drip, trying to stop the leak completely could cause the packing to overheat. One drip per second is okay. If it was 10 drips per second I would probably let it go for a while. When it is a steady stream you need to adjust.

If the packing nut tightens all the way down without sealing then you need to replace or simply add more packing. This is a job best done with the boat out of the water. Back the gland nut all the way off. Take a look at the gap between the shaft and the inner diameter of the gland nut. Go to West Marine or similar store and buy new packing material, the largest stuff that will fit in the gap (It should be available in a wide variety of sizes). The packign will look like a piece of rope. Wrap it around the shaft and cut to length, ideally the ends will just meet. Slide the gland nut back on and tighten till snug, then back off just a tad. Tighten to stop the leak once you are back in the water.

On a direct drive boat this is a very easy task. On a V-drive it is a major pain only because the stuffing box is under the engine.

Rudders sometimes have a packing and sometimes have a seal. If it is a packing then the same instructions apply. If it is a seal then you need to pull the rudder, pry the old seal out, get a replacement and reassemble. If you can get the old seal out fairly intact and take it to a commercial bearing and seal shop they can easily find a replacement just by measuring the old one. The dealer should also be able to get you a replacement if the boat is not too old.

It is also possible that your leak is coming from some place else, so I would not go too crazy replacing seals and packing until I had identified the source of the leak.

Other possibilities:
1) the water circulating pump. A leak out the shaft indicates the bearings are about gone and it needs to be replaced yesterday!

2) Raw water pump: same story.

3) A crack / split in a hose: replace the hose

4) A crack in a ballast tank: bad news!

5) Do you have a heater? It is common for the heater core to spring a leak.

6) Quit burying the bow in your wake! I know that the girls up front are just asking to get wet, but its getting your boat all wet!

Great info, Rod. If that does not work, buy an extra bilge pump.

Have you ever seen the tampon comercial, where the couple is in the rowboat?

I hope that your dealer will be honest with you about the price to fix it, I have had problems with mc dealers telling the truth.

i just went and looked at a buddies x7 who was having the exact same problem, after fighting it for a year he finally discovered it was the rear vent, every time he stopped water would poor in, and he couldnt leave his boat in the water overnight at pillsbury beacuse the way the wind would blow the light chop would splash right into the vent, maybe not your problem but he said it was the very last thing he would have ever thought and it was letting in an amazing amount of water....

Couple of things to add, it should only drip once every 30 to 40 seconds and you should use multiple strands of packing material making sure you offset the spot where the ends of the rope come together.

I replaced my stuffing box with GFO drippless packing and it does not leak very much water by it at all. Here is a the http://skidim.com/prodinfo.asp?number=GFO1/4X24 that I used but make sure you get the correct size for your boat.

Rod,

Thank you for taking the time to write all of this out, that is exactly what I was looking for. I appreciate everyone's input, I will take this thing on next weekend and let you know how it goes. Any other advice is appreciated. Hope I can return the favor.

Just don't forget, if that won't work, you could always try the rowboat thing.

Two more places to check, your swim platform mounts and your speedo pitots. I found that the metal tubes that the hose coming from the pitot attaches to had cracked, probably due to freezing water. On my boat they were in the trunk behind the trim panel. It's not an MC but our boats use the same KM computer and speedos. I had a significant leak from this. Here's a link with a pic.
http://www.epicmarine.com/speedo.html

Here's a doc on repacking your shaft seal.

http://www.epicmarine.com/docs/repacking.pdf

Is it wet anywhere else? My MC 205 leaked from the bolts that attached the fins to the hull and the rub rail. It took me about 5 months to figure it all out.

Get a dripless packing gland so you never have to worry about it again.