Exhauste smoke...?!

[MBO]

Hello.
I have i 1998 Ski Marine (some 1800 hours) that runs perfect but on full gas at around 4000 rpm it starts to come some white smoke in the exhaust...

Is this normal or is the engine leaking water...?!

Ive had my boat since august so im quite new as a nautique owner.

Thanks!

Mattias, Sweden

[jasper]

Have you checked your impeller or temp lately? The white smoke could be a number of things, but I've seen boats with bad impellers start smoking at higher rpms as the very first symptom of one going out. Obviously, it doesn't last too long since once it gets to this point, the engine won't/shouldn't run much longer.

[MARK-S]

What does the smoke smwll like? Burnt Rubber smell would lead to impeller. Is it heavey exaust steam or smoke? Gas or fiber burning smoke?

[8122pbrainard]

MBO,
This time of the year in Sweden you should be getting cooler ambient temps so the white smoke may be normal. Is this the first Fall you have run the boat? If the engine temp is fine, then just go for it!! The engine is always leaking water - all the cooling water pumped in, exits into the hot exhaust at the tail end of the exhaust manifold riser. With colder ambients, the warm moist exhaust reaches the dew point and you get the white "steam".

[TravisFling]

8122 is right. Remember, white "smoke" is actually steam, so it's just water getting hot and is perfectly normal, especially at higher rpms, as more water is trying to cool hotter components, so it's vaporzing. Blue smoke is oil burning, or rubber (like an impellar) and black smoke is unspent gas. Hope that helps!

[DanielC]

I have a 1997 Ski Nautique, and ski early and late in the ski season, with a drysuit.
Ther have been some times on a cool morning, when the water is still warm, that I have almost lost sight of the boat from the fog coming from the exhaust.
What is a Ski Marine?

[DanielC]

I believe that the GT-40 engine's raw water pump should pump about 5 gallons (19 liters) of water in 15 seconds, at 3000 engine RPM.
At home, when I run my Ski Nautique with a garden hose to supply water to the engine, at an idle a 5 gallon bucket will slowly fill, and at around 1000 RPM the engine starts wanting more water than the hose can supply. Plumbing in Sweden may supply a different amount of water.
Like it was said, if your temperature gauge reads in a normal range, and there are no unusual smells coming from the exhaust, you probably are OK.
I would suggest that you put a new raw water pump impeller in the water pump, beginning next Spring. I am going to assume that you are going to lay up the boat soon for winter.

[8122pbrainard]

Daniel,
MBO came back on CCfan after we answered the same question and the "Marine" turned out to be a Nautique. Must be the literal translation - I've never really thought about the word "Nautique" much but now I have!!!