Steam in the exhaust: Problem?

[jnkelliott]

Question. New to me 2022 Fisherman with the Yamaha 250, 92 hours on the clock. Engine temps are spot on, the tail tell is weak (I’ve been told that’s a common trait on this engine) and, I noticed steam at idle. External water temp is 55 degrees.

Is this a shot impeller, blocked cooling passage way, or steam from colder ambient water temps?

Thoughts?

 

[igblack87]

At first glance, this doesn't look like a huge issue. Did you just start the boat? What is the temp outside? After you run the boat, does the exhaust trail disappear?

I have a much older engine F250 from 2006...it does the same thing at start up and idle then the exhaust trail goes away when the engine has had a second to "wake" up.

As for the tell tail, pee stream...do you know when the last service on the engine was done? Do you have records from the previous owner on all the maintenance?

Sounds like you should run it! Good luck!

 

[seasick]

May be nothing to worry about. As mentioned, it usually will stop as engine warms up. When you start your car on a cool day and see steam (actually condensation) do you worry

 

[Sardinia306Canyon]

(I’ve been told that’s a common trait on this engine)

Jupp, all 3 of my F300's what is same outboard as yours did the same, very weak peeing.

A common issue of this motor is that if used for long times idling or low rpm it clogs the upper exhaust and that will lead to excessive and noisy bubbling thru prop exhaust.
It's probably this steam what clogs the low rpm orifice between midsection and silencer, exactly there where your is steaming, in my case it was kinda slat crystals building up. However this happen only if engine run for long hours at low rpm, idle to maybe 1000 rpm when exclusively the upper exhaust is working
I noticed that my new Honda BF350 do steam, but honestly i don't recall that my F300's did that, at least not as shown in your photo.
Ehat kind of weather did you had when you took the photo?
Does it change; some times more, sometimes less?

Chris