Noticed a small surface hairline crack on the water outlet elbow on my 100M/BN2. It is on the flat edge towards the carb side of the engine. Does not appear to go all the way through. No telling how long it has been there, could be years. I can of course take it off to inspect further but think just watching is sufficient ? Hate to dump all the antifreeze,etc but then again, do not want it to suddenly crack all the way either as I'm going down the road !