I was winterizing the boat, when I took the drain plugs out of the exhaust manifold, one of them just crumbled. The engine is a '99 502 with stock exhaust. Is there anything that I need to do to make sure none of the plastic clogged the line and where do I find a new plastic drain plug? Thnks for the input.
Scott

The plug is avaible from either a merc dealer, West Marine, Boat Fix, etc.
I always keep a few extras as the flange part always seem to break off. I usually can just tap a screw driver into the the plug body and unscrew it. Doubt it will clog anything if it crumbled as you say.

I found out from 9 years of using that blue wing nut that their a lot less likely to break if you just snug them slightly,the o-ring does the work. I think when their overtightened the expansion & contraction of the heating & cooling of the engine causes extra fatigue on them.