Is this smoke suspect?

Posted by SweetSeaCaramel@reddit | sailing | View on Reddit | 30 comments

I have a weekend of sailing ahead and last Sunday this is what it looked when motoring back. It's a 6hp four stroke japanese outboard in a well and it got a full service in spring 2025.

I do not remember it being there when motoring out of the marina. But it lasted maybe 5 minutes when i started it and went back. It was also spitting a bit of water as you can see. It's more gray than blue imo.

No suspicious noise or vibration and it went away after those \~5min.

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DarkVoid42@reddit

what is that fitting connected to ? your outboard looks like it has ok cooling so chances are the exhaust is not from the engine.

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SweetSeaCaramel@reddit (OP)

That's connected straight to the motor's exhaust. Maybe 30cm or 40cm. The outboard is in a well and very accesible/serviceable since the lazarette has a wide double door opening. I will verify that it is well secured with new zip ties next trip.

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JiffyMcPop@reddit

Well if he wasn’t a sailor before, he will be soon

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SweetSeaCaramel@reddit (OP)

Oh, I will! Barely can think of anything else.

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jocrow1996@reddit

Hey! I had a similar issue when some water got into my fuel from condensation. Very annoying. IMO, if it went away and it’s running okay, I say send it.

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SweetSeaCaramel@reddit (OP)

The cap of the tank is banged and I cannot close the air valve anymore. So that might be it?

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jocrow1996@reddit

That’s actually what did it to mine lol. I lost the air vent cap and it got rained in.

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SweetSeaCaramel@reddit (OP)

Alright then looks like a match. Did you dispose of the fuel or just changed the cap?

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twrodriguez@reddit

Yes. Probably. What's the engine water temp? The clip just keeps looping and it's too short. It should not steam, that means the water is boiling. Iirc, my diesel runs at about 180f

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SweetSeaCaramel@reddit (OP)

This one is gasoline and sadly has non sensors.

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drewander123@reddit

Impeller cus no water pumping out and also possible your mixing elbow might be needing to get replaced. But start with checking your impeller. Easy to fix

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SweetSeaCaramel@reddit (OP)

Thanks

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Nephroidofdoom@reddit

Is there any ethanol in the fuel? Could be vapor from that, especially if it’s an 80/20 mix.

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SweetSeaCaramel@reddit (OP)

Thanks. No it is straight from the pump.

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pab_guy@reddit

Exhaust should go through the propeller hub. The upper exhaust is meant for relief when the motor is idling, but can also throw extra exhaust.

If it’s powered and pissing and not making a funny noise I would say you are fine, but I would check the prop hub if you can, maybe you got some barnacles or something lol

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SweetSeaCaramel@reddit (OP)

Thanks!

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No-Sail-6510@reddit

Ooff. That’s not smoke that’s steam. Looks like your impeller is out or something.

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pab_guy@reddit

See the stream of water in the photo?

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elanghe@reddit

There should be water coming out of that exhaust port as well.

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SweetSeaCaramel@reddit (OP)

Hey thanks! So it is normal tonhave eater comming out of the exhaust then?

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Brief_Preparation698@reddit

I dont know about the smoke, but it doesnt look like your water pump is moving any water. Last time you replaced the impeller?

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futurebigconcept@reddit

He said it's an outboard, and you can see a separate little stream of water at the centerline. I'm guessing the cooling system is built-into the outboard, not a separate water pump like a diesel has.

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SweetSeaCaramel@reddit (OP)

Yes in the center there's a good 30cm jet. Impeller was changed last year.

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SweetSeaCaramel@reddit (OP)

It was 22 or 24 at that time.

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