OMC Stringer 800 Water Leak

[minnetonkaboater]

I have a 1984 21' Larson with a 5.7L Chev engine and an OMC stringer 800 outdrive.

I have been trying to diagnose a water leak and have made the following observations:

1. When sitting in the water without the engine running there is no water leaking into the bilge.
2. With the engine running and the boat fully immersed in the water, water is leaking somewhere in the intermediate housing next to where the tilt motor is mounted.
3. When th engine is turned off, water continues to leak in thru the intermediate housing with the same intensity. A steady stream downward at about a 45 degree angle.
4. The boat is kept on a lift. If I have the boat out of the water, except for enough of the lower drive for water intake, I do not get the leak in the intermediate housing.
5. Due to access, I can't tell, or see, exactly where the water is coming from but like I said it is next to the tilt motor more toward the lower center of the intermediate housing.

Does anyone have an idea what the source of the water leak is?

Due to age, if I have to pull the lower unit and then the intermediate housing, I will replace the impeller and the transom boot while apart. My tilt and trim does not work either, so I will diagnose and repair that at the same time, as well.

 

[WizeOne]

Re: OMC Stringer 800 Water Leak

My suggestion is to remove whatever is in your way and get down there with a lite and see what is happening. There is just nothing else down around the tilt motor area that could be leaking, other than a breach in the boot or boot seal or a corrosion hole.

I can't fathom how at one moment with engine off it is not leaking, then the next momemt with engine running it is. Then again, when you shut the engine off, it continues to leak????

 

[minnetonkaboater]

Re: OMC Stringer 800 Water Leak

First of all, this is a very tight installation with the engine shoehorned in and very tight access behind the block.

To back up a little, the first leak I discovered was on the starboard side. It was leaking from the lower hose on the exhaust pipe. I had no leaks for 25 years and all of a sudden I have leaks. Turns out the clamp was not installed correctly at the factory as it was off the hose on one side. When I corrected this I took apart the exhaust elbow, the hoses and the exhaust pipe on that side. Is there any way I could have reinstalled something wrong? I can't imagine what it could be, but it seems like such a coincidence I have another leak at the same time.

Also, I had the boat sitting in the water and no leaks from the outside at all until I started the engine. Then it kept coming in even after I shut the engine off. Is there any way water is coming back in thru the exhaust in the lower unit that is below the water line? When I run the engine with the exhaust above the water line it does not leak.

Puzzling?

 

[bruceb58]

Re: OMC Stringer 800 Water Leak

Could easily be the boot. When the boat engine is running and it is vibrating that boot, any small crack in the boot may then open up a little. Also, any torque that the engine has will translate into some flex of the boot, especially if the stringers are getting softer with age. You can very likely change the boot without removing the drive.

 

[minnetonkaboater]

Re: OMC Stringer 800 Water Leak

I tried to do a little more troubleshooting and determined for sure there is no leaking until the engine is running and continues after it is shut off.

1. When the boat is in the water without the engine having been run yet there are no leaks.

2. When the engine is running and the boat is only in the water up to the water intake there are no leaks. In this case, the exhaust is exiting above the water line.

I did notice there seems to be water coming out of the upper gear housing that I don't think should be coming out where it is.

3. When the engine is running and the boat is in the water, water is leaking into the bilge either from the intermediate housing or the upper gear case housing, or both.

Water continues to spray into the bilge even after the engine has been shut off, as though a passage has opened up somewhere from outside allowing water to flow into the bilge.

I am wondering if several of the seals have given out in both the intermeiate and upper gear case housings.

I just don't understand why water does not leak into the bilge, when the boat is sitting in the water, until the engine has been started.

Any other ideas???

 

[WizeOne]

Re: OMC Stringer 800 Water Leak

Hate to repeat myself, but you're just going to have to clear out whatever is in the way so you can take a look. There is nothing down in the area that you suspect, that would leak, except for the boot. And that certainly is not related to running the enine.

I have to remove a rear seat assy and back panel to get to mine so it is not that unusual that there is tight quarters.

 

[bruceb58]

Re: OMC Stringer 800 Water Leak

if you can't see down there, stick a digital camera down in the bilge and snap some pictures. Just don't get the camera wet.

 

[minnetonkaboater]

Re: OMC Stringer 800 Water Leak

Well, WizeOne, you were absolutely right. For some reason if you lower the boat in the water and not run the engine, water did not leak in. But, on closer inspection, there is a 1/4" tear in the bottom of the boot on a fold.

So ,finally solved and I will try to replace the boot without removing the lower unit. If I can get the old one off that way, I should be able to get a new one back on.

Thanks again to all for the input!

 

[WizeOne]

Re: OMC Stringer 800 Water Leak

Glad you found it. Now get back out there and impress all those chicks lounging around at Lord Fletchers.