Mercury "No Paint" Outboards - Why Paint and Why Not?

[Gordon02]

I've owned my Promax for 18 years now and have always wanted to know the "Why" of no engine paint. I just read the term naked in another thread referring to a no-paint model, but I have not understood the real reasoning for painting some, but not all.
I own several outboards now and have had dozens more over the years - all have been painted with the exception of my 1999 Promax on the back of my Allison XB2002. After rebuilding some 100 motorcycles and outboards, the corrosion I've seen from salt use and dis-similar metals as caused by stainless, steel, and aluminum engines galvanic corrosion has been on the inside. My naked motor looks better than any of the painted ones I've ever owned, so why or why not paint?

Thanks for the inputs! Gordon

[XstreamVking]

They are "naked" to release heat more easily is what I was told by a mercury race tech at merc school. I have a feeling they are un painted just to look different than production motors. It could also just be a tradition left over from the past when they were more concerned about the motors performance than it's looks.

[FMP]

Probably ran late, out of paint. Black will heat soak and shed/dissipate heat better than other colors. Not sure about a thin layer having an R value which negates. Naked looks good

[aeneas]

Race engine. Probably also easier to find cracks, leaks and damages on a naked block.

[NoRdO]

Race engine. Probably also easier to find cracks, leaks and damages on a naked block.

^^This one gets my vote. Probably makes rebuilding cleaner as well, no need to remove/blast off all that old paint... Just thinking of all the old seadoo rotax motors I've rebuilt... there are tiny white paint flakes all over my garage...

[mach351]

The alodine they are coated with provides good corrosion protection.......plus it looks bada$$

[flabum1017]

Racers could care less about paint, they just want to win

[FMP]

The alodine they are coated with provides good corrosion protection.......plus it looks bada$$

Chromic Acid treatment pre paint? Just as an aside
Endura coatings paints, website has some good products.

[flabum1017]

Chromic Acid treatment pre paint? Just as an aside
Endura coatings paints, website has some good products.

Could go chrome