5.0 OMC lots of smoke and water in bilge

[Hammer Down]

'94 or '95 Chris Craft Concept 197 with 5.0 liter OMC and cobra outdrive. Boat was winterized and all the fluids changed by the shop back in the fall.

Yesterday my co-captain and I took the boat out for the first time this year to blow the cob webs out. Boat started and ran fine. I was expecting a lot of smoke from the fogging oil burning off, but there wasn't any. Idled out about 300 yards then took it to about half throttle. It didn't jump out of the water like normal but once it got up to speed it was fine, made a big loop then slowed back down when Co-Captain thought he smelled smoke. I didn't see or smell anything so we shrugged it off and opened it up to about 3/4 throttle. After about 10 seconds of this thick white smoke started coming up from between the floor and gunnels on his side. I shut it down immediately, opend the engine cover and lots of acrid white smoke and a kind of popping sound like something was burning but no fire. Bilge had a pretty good bit of water in it and continued to fill even after the engine was off. Luckily another boater saw the smoke, headed our way, and towed us in. When we got it out of the water the only thing I noticed was the exhaust bellow was almost completely torn in two. My working theory right now is that somehow the water coming in was keeping the exhaust from getting out but I could be wrong. Any chance this is a simple fix (we are both very mechanically inclined) or do I need to go ahead and get it in the shop?

 

[Maclin]

Re: 5.0 OMC lots of smoke and water in bilge

The exhaust hoses inside the engine compartment burned up, right? That would be from no raw water flow causing a serious overheat. Did you notice what the emp gauge showed? Are you sure all of the engine and manifold drain plugs were re-installed? A blown soft plug or two also would drain the engine's cooling system coolant as fast as it could come in and perhaps reduce water flow thru the exhaust enough to cause that.

 

[Hammer Down]

Re: 5.0 OMC lots of smoke and water in bilge

The burning exhaust hose would explain the smell. I'm gonna go back out to the marina in the next day or too with a mirror to try and get a better look around. Don't recall what the temp gauge read, I want to say it was low maybe even 0, but then again the gauges have been crapping out lately so its hard to say.

 

[Maclin]

Re: 5.0 OMC lots of smoke and water in bilge

Water temp gauge sender has to be in water, steam reads almost zero

 

[Hammer Down]

Re: 5.0 OMC lots of smoke and water in bilge

Ran out to the marina at lunch found a hose clamp and what appears to be some pieces of the impeller in the bottom of the bilge. This is our third summer with the boat, but it didn't get used but a couple of times last summer so we didn't replace the impeller. Hopefully it won't be a incredibly expensive lesson.

 

[Maclin]

Re: 5.0 OMC lots of smoke and water in bilge

Are you sure those weren't already in the bilge from last year? Did you see a hose disconnected somewhere? Usually impeller pieces do not make it out of the plumbing and onto the bilge floor, just sayin'....

 

[Idlespeedonly]

Re: 5.0 OMC lots of smoke and water in bilge

It would be next to impossible for impeller pieces to make their way into the bilge. What part is the clamp off of?

 

[Hammer Down]

Re: 5.0 OMC lots of smoke and water in bilge

I honestly don't know where they came from or how long they've been there. I just thought I'd share in case it helped someone more knowledgeable than myself come up with a diagnosis.