Water out one side of exhaust?

[Tanner]

I can't for the life of me figure out why the boat is only getting water out one side of the exhaust. I seem to remember it coming out both always, but now it only seems to come out the port side, but not the starboard. The starboard exhaust bank has water going to it though.

I cut the muffler open and found big problems inside of it, so I gutted it and re-fiberglassed it. Still same problem. And yes I made sure there wasn't a rats nest inside the exhaust tubing.

Does anyone else seem to remember if water comes out both exhaust ports or just the one when running on the hose?

[whitlock87]

YES, i have water coming out of both on my Marine power 5.7

[OldeBoy]

Yes I have water coming out of both on my Mercruiser 350 Mag. (on garden hose)

I also had water coming out of both on my Moomba with an Indmar 350. (on garden hose)

[OldeBoy]

Have you taken any temperature readings on your exhaust risers? Is one significantly hotter than the other?
When you say the starboard has water going to it, What exactly do you mean? I have found a piece of impeller in the water supply line to the exhaust manifold. Did you pull this line apart and inspect for obstructions?
What big problems did you find in the muffler? Were they due to overheating/not enough waterflow?

[chpthril]

With the engine running, pull the hose off the suspect manifold and see if it has water flowing in the direction from the engine to the manifold. This will point to which direction you need to go. No water.....look towards the engine. Flow.....look for a blockage in the manifold.

[Tanner]

With the engine running, pull the hose off the suspect manifold and see if it has water flowing in the direction from the engine to the manifold. This will point to which direction you need to go. No water.....look towards the engine. Flow.....look for a blockage in the manifold.

We did this.... there's equal flow coming out of both manifolds. First I pulled the hose feeding into the bottom of the manifolds and saw plenty of water. Then I pulled the exhaust baffles and watched the water coming out of the risers. It was equal as well. The weird thing is, this is causing the motor to heat up. Although I guess that could be a totally separate issue. Impeller and housing look pristine. I guess the supply pump could be going bad? Still dunno why that would make one side of the muffler have water and not the other.

As for temp readings between manifolds, to the hand.... they are almost identical.... but no I haven't stuck a heat gun or any gauge to them.

Someone asked what was up w/ the muffler.... I was concerned a rat had made a nest inside. When I pulled it, I could hear stuff rattling inside. Plus I could feel pieces floating around inside, so I cut it in half to take a peak. Wow, the thing had cannibalized itself, There were giant chunks of fiberglass shards floating around. I was worried about them blocking flow, so I took them out and gutted the internals of the muffler before fiberglassing it back together. Dunno why it came apart internally. Never once have I had a heat issue until right now.

[boatwakes]

The muffler came apart because of heat from lack of water. If there is water coming out of each exhaust riser (the center rise exhaust elbow on top of the exhaust manifold) and going into the exhaust hose connected to the riser which is then connected to the muffler, unless there is a water crossover between mufflers there is water coming out the back or going into your boat somewhere. Can you post a pic or a video of what you're describing? There is always a heat differential between risers when water flow stops on one side.

[Tanner]

You say mufflers... But theres only one giant muffler... Its one big crossover chamber. Even before I gutted it.

But I think ive narrowed it down to a clog somewhere in the riser. Having it pressure tested this week. I went back and looked, and it seems like the one riser isn't putting out as much water as the other. The thing I can't figure out is where is the water going? There's no water in the oil, and like I said, I'm getting plenty of water to that bank from the circulating pump.

[strohlde]

Replace your riser gasket?

We actually blew a hose off the riser on one side last year, pulled it apart and the seal had failed which may have been the cause as the cooling water was leaking into the gas chamber. Not sure if it's related or not. We may have also still had some impeller bits in there that the 'explosion' finally blew out of the system.