Uncovered the boat after a very cold winter in PA and found the starboard side exhaust manifold and riser with a white chalky residue. Any thoughts? The motor was drained and antifreeze poured in from the top down, about 3-4 gallons. I'm yet to start it since being winterized, just wondering if anyone had any immediate thoughts. Both manifolds and risers were replaced last winter and were used, with no problems, all of last summer.

a lot or a little. It seems I have seen this on engines and metal after a long winter. Dont know if the metal sweats a little. Or maybe its just the antifreeze that dried up

Tough to say since I've never seen it before. It's enough that I can write my name in it and easily see it...hoping it's nothing but I'll find out soon I guess.

yeah I dont think it anything serious probably just corriosion from something left over that was on them. Maybe overspray if you fogged it.