Smoke and water from exhaust

[NE Grady 208]

Took my 208 out for first time today. She has an F200 four stroke with light use. I noticed white smoke coming from exhaust while I was out. came back to the dock and restarted her because it was bothering me. There was white smoke and sputtering water coming out of exhaust. i have not seen or noticed this before. Any chance this is normal?

 

[Bloodweiser]

Any water in the
Motor oil ?

 

[Summertop511]

Sounds like the dry exhaust issue.

 

[seasick]

Measure the engine water temps to see if they are cooler or hotter than you would normally expect. Although it could be serious, it could be simple as a stuck open water pressure valve (poppet).
Do you remember if the motor spit water out of that upper port before?

 

[SmokyMtnGrady]

I think it means we are getting a new pope?

Cold engine , cool outside temps with cool water has produced something similar in my boat. I guess what I am saying is sometimes atmospherics influence the appearance of the exhaust. Then again white smoke could mean something truly wrong.

 

[seasick]

Although I am not 100% certain, I think there are a few different scenarios. When the motor just blows 'steam' it can be due to the temperatures and humidity. I see this often when there are fog warnings and high humidity with coolish water temps
The second situation is where the motor blows 'steam' AND spits water out of the dump port near the top of the exhaust stack.

In the cases I have experienced the smoke on a Merc motor, only one engine had the issue. If the cause is just the weather, you would expect both motors to act the same I would think.

 

[NE Grady 208]

Thanks everyone. I don’t remember seeing the water from exhaust before. I bought the bought last summer and had the lower unit removed and scoped as part of survey. I was told this engine did not have the exhaust issue. Really hoping that is not what is going on. I will check the water temp and poppet valve as suggested. Also, what I saw as white smoke was more likely steam. Water temps are still pretty low. If I let the engine idle, is some water from the exhaust port ok?

 

[seasick]

I think excess water when the pressure valve trip is passed out that port as well as into the exhaust. If that theory is correct it would explain why I think the poppet valve may be stuck open. Note that if that valve is open at low revs, the mot usually will overheat at lower speeds. If the ocean waters are cold, that might be enough to keep the motor from overheating. Unfortunately, looking at the water flow diagrams doesn't really help explain when and when water flows into what

I am also not sure that the smoke is steam exactly For steam it would have to be pretty hot, basically overheating and boiling. It may just be condensation since the air is cool but the exhaust water is hot and moist. The normal flow of exhaust is out the prop and there is no visible condensation since it is under water. Condensation is normal, steam is not a good sign.
Then again, I could be totally wrong. Wouldn't be the first time!

 

[SmokyMtnGrady]

You guys ever see your car exhaust on warm humid day when start it up? No,not really? What about a cold morning or cool morning ? Yep? Why? It's not steam per se and definitely not cooling water getting into the motor. It's chemistry and physics. When the motor takes in air that has moisture in it, water vapor , and compress it and heat it with an explosion inside a combustion chamber the exhaust gas will have a few things in it . It will have carbon monoxide,carbon dioxide, dihydrogen monoxide ( aka water) and other stuff. So, the warm moist exhaust gasses hit the cooler air and condenses rapidly and voila you get white looking exhaust. It's like steaming up your shower. Your skin would fall off if you actually blasted steam water vapor onto it as steam is well over 212 degrees F. That is the phenomenon I am suggesting here. It normally happens when your motor is cold.

Now somebody cleverly pointed out it's not on both engines and I admittedly did catch that. So ,maybe it's not atmospherics here at play. You can eliminate my theory by taking your boat out in the afternoon when it's warmer . If it's still happens then maybe take it to a mechanic for their opinion?

 

[Capnjim7]

Hope you are right about the exhaust tuner. My 05 225s had buildup but no apparent decay with 300 hours. I had them both done to be sure and one of them was pitted so badly on replacement that I was told if I had done one more offshore fishing trip it would have failed. I hate to go to the worst case scenereo but if you are seeing water bubbling with steam you need to get it to the dealer asap to be sure. What year is the motor?

 

[seasick]

You guys ever see your car exhaust on warm humid day when start it up? No,not really? What about a cold morning or cool morning ? Yep? Why? It's not steam per se and definitely not cooling water getting into the motor. It's chemistry and physics. When the motor takes in air that has moisture in it, water vapor , and compress it and heat it with an explosion inside a combustion chamber the exhaust gas will have a few things in it . It will have carbon monoxide,carbon dioxide, dihydrogen monoxide ( aka water) and other stuff. So, the warm moist exhaust gasses hit the cooler air and condenses rapidly and voila you get white looking exhaust. It's like steaming up your shower. Your skin would fall off if you actually blasted steam water vapor onto it as steam is well over 212 degrees F. That is the phenomenon I am suggesting here. It normally happens when your motor is cold.

Now somebody cleverly pointed out it's not on both engines and I admittedly did catch that. So ,maybe it's not atmospherics here at play. You can eliminate my theory by taking your boat out in the afternoon when it's warmer . If it's still happens then maybe take it to a mechanic for their opinion?

You may have missed the comment about the non smoking motor not spitting out the dump port. Maybe it's a combination of two conditions; The atmospheric conditions that cause the 'fog' to form in addition to the fact that the wet mixture is going into the open atmosphere (the dump/bypass port).
The motor I mentioned has had this phenomenon occur several times and always after a decent run and while slowing to idle as the boat approaches a no-wake zone.
It's still a mystery as to why but I suspect that water is getting to and filling the dump port water chamber causing the water to overflow out the dump port. I just can't figure out why. It could be a poppet, a leaky divider plate, a blocked exhaust stack plate or a leak between the cooling column and the exhaust stack. I have read on other boards that the 'smoking' condition on Optis is normal but I don't buy that argument. If it were, it would happen on both motors and it doesn't. I shouldn't be hijacking this thread but I was hoping that a determination of the cause on the Yami might help me figure out the Opti issue.

 

[Bloodweiser]

Thanks everyone. I don’t remember seeing the water from exhaust before. I bought the bought last summer and had the lower unit removed and scoped as part of survey. I was told this engine did not have the exhaust issue. Really hoping that is not what is going on. I will check the water temp and poppet valve as suggested. Also, what I saw as white smoke was more likely steam. Water temps are still pretty low. If I let the engine idle, is some water from the exhaust port ok?

did the surveyor mention if it had the exhaust kit installed? or just no exhaust issues.

 

[NE Grady 208]

First, thanks again for the input. It is really valuable to be able discuss and work out issues in this forum.

So, not a great day. Started the engine, was looking for the smoke and noticed water coming out of bottom of cowling. Shut it off. Removed cowling and restarted. Saw lots of water come out from underneath black head cover. Left and asked marina to have their guy look at it thinking maybe a loose hose or fitting. Nope. See the attached picture. Blew a hole in the block. Yard told me it is likely previous owner never changed internal zincs and corrosion is tough to see because it came from inside the block. They presented three options 1) grind out the hole, use JB weld and see if it holds 2) new block cover or 3) new engine.

My choice at the moment is have another beer.

 

[Bloodweiser]

Man sorry to hear that . The beer is the best option for the moment, I sometimes have my best ideas while drilling a few bottles, though I’ve been told my typing is crap

 

[seasick]

Have the head cover removed and inspect what's underneath. If not too bad, replace the head cover. That would be my approach.

FYI, your picture wasn't on your post.

 

[NE Grady 208]

Seasick, thanks for the reply. Let me try the picture again

 

[NE Grady 208]

 

[Summertop511]

Is that behind the thermostat? Trying to get an idea where that is. What does a new power head cost? Grinding down and repairing will maybe get u a season.

 

[seasick]

I can't tell what I am looking at. I assume the thing on the right is the flywheel. Are we looking down towards the lower cowling from the top?
If that hole is corrosion, I think there may be more extensive damage. Secondly, did they did it out to make it that big? It seems like it would have leaked a lot of water.

 

[NE Grady 208]

The hole is about the size of a pencil eraser and is directly behind the thermostat housing. The rest of the housing on all sides looks clean. I was told the copper on the end of the thermostat could cause housing to rust. It has not been touched yet. I am going to clean it out and see if JB weld will hold.