Whitish Gray Powder Around Cylinder Head

[luckyinkentucky]

I have a '94 Vindicator 200 with less than 400 hours on it. When I was checking the compression today I noticed that the head above the #6 cylinder has some chalky whitish gray powder residue on the head itself. It isn't very thick, but more like a dusting has taken place. I'm positive that it's not dirt or dust from an outside source, but what could be the cause of this?

 

[5150abf]

Re: Whitish Gray Powder Around Cylinder Head

sounds like corrosion to me,it is probly aluminum "rust".
Almost all metal corrodes, steel rust is brown,copper turns green, aluminum rust is white.
It could be electrolisis too, this is caused by current but this usually happens below the water line.
Is the paint okay in this area?
If not I would clean that spot really well and put some touch up paint on it.
Check the anode on the motor too, usually a small unpainted block on the lower unit somewhere.
Either way I don't think it is going to cause a problem, unlike steel, aluminum rarely "rusts' through.
Theres my 2 cents.

 

[F_R]

Re: Whitish Gray Powder Around Cylinder Head

Is it under the paint or on top of it? Powdery white stuff under the paint and paint flaking off the heads is very common on motors used in salt water and also happens to a lesser degree in fresh water. Not to worry, it doesn't mean anything is wrong.

If it is a dusting on top of the paint, it has to be coming from an external source, maybe being blown there from some different area by the flywheel?

 

[luckyinkentucky]

Re: Whitish Gray Powder Around Cylinder Head

It's on top of the paint. I suspect it may have always been there, because I noticed it when I bought it, but didn't pay much attention. The previous owner was an Air Force Officer and bought the boat new in Texas. I remember him saying that he did fish some saltwater areas down around Corpus Christi, but only for a total of 6 hours. Then he moved to Missouri and only used it for a total of 20 hours in the Mississippi, and a few area lakes. When he retired he brought it to Indiana, and only fished Patoka Lake for 150 to 200 hours or so and sold the boat. All in all over a 12 year period he only put maybe 300 hours on the engine which isn't bad at all. I suspect some of the minor repairs that I have done are from 'sitting damage'.