[larry luckham]

I have a Mercury 115 inline 6. The original purcase receipt says it's a 1985. It's on an 18' Hydrasport that sits at my dock most of the time (saltwater). The boat get's little use during the winter, but the engine is kept tilted clear of the water.When I went out to check the battery and give it a try at starting for the first time this season I found that there was no water stream coming from the pee hole. Several people suggested that it might just be blockage at the pee hole. I followed their suggestions to check that with compressed air. I'm able to blow completely through the pee hole, the tube from the top cylinder and back through the fitting on that top cylinder right back to the lower unit.I don't have an exploded view of the lower unit and water pump, but it seems to me that air should not be able to pass freely around the impeller. That suggests the impeller has disintegrated.One other thing I noticed when I started the engine briefly a second time is that there is a stream of exhaust coming from the pee hole.Does the disintegrated impeller sound like the likely cause? Does the exhaust from the pee hole suggest something more serious? Is there a further diagnostic I can do to help isolate the problem before getting out wrenches?

[DJ]

larry,Air would be able to go through the entire system.I believe your impeller is gone.

[Spidybot]

The water jacket is separated from the exhaust to ensure cooling capacity around the head. A mix of water and hot exhaust bubbles would make proper water circulation impossible. The used water and the exhaust are mixed later in the circuit and emerged through the exhaust port/prop centre. At the point where the peehole is there should be nothing but water. If your impeller is dead things are not normal, though. Water does not circulate/fill the jacket and exhaust might make it's way to the pee.If there is no other signs of blown gaskets or leaks I'd replace the impeller with related fittings and expect it to be OK.

[jwinslow]

Just this weekend I experienced a similar problem. Water stopped comming out of the pee hole. Instead of water coming out, warm air came out with a slight component of blue smoke.

Once the engine started it would run fine for about 20 minutes. It then would show signs of loosing power. Also, white smoke or steam seemed to rise from the water in place of the usual thin light blue smoke.

I took off the coolant plate on the power head, and turned the engine over without spark plugs with the earmuff flusher with water running through it. Water gushed out of the bottom below the outside of the the lowest cylinder. I assumed maybe the gasket blew, so I replaced it, expecting to solve the problem. Replacing the gasket did not change anything. It seems that though water came up from the lower unit, there was not enough pressure for the water to make it to the top cylinder.

Also noticed whitish sludge coming out of bottom spark plug hole, when turning engine over without spark plugs.

I checked the compression. It was around 100 for each cylinder, while the engine was cold.

Any thoughts?

[hourstonglascraft]

white sludge in #4 or #6 cylinder and a loss of power hmmm, i have had this a couple times the white sludge is water getting into that hole either from the exhaust gaskets or bottom crank seal , from what I know the water getting in only #4 or #6 indicates the bottom crank seal, be carfull dont run it to much like this or you will be like me with a blown up outboard

[emckelvy]

Water ingested into the engine, in concert with loss-of-water/circulation problems, is more likely due to bad exhaust manifold gaskets or a perforated exhaust baffle.

You'll need to remove the exhaust manifold cover for inspection.........ed

[Chris1956]

Larry, On that 115HP, water is supposed to mix with exhaust under the port side exhaust cover. Of course the water jacket should be full, and preclude the exhaust from entering it.

I would replace/rebuild the waterpump and see if the situation improves. if you still get exhaust into the water jacket, you may have a powerhead base gasket problem, or something.