i'm no guru, but i have experienced my weep hole being plugged on my mc-1 (pre-alpha if you wish). i'd be worried if your in cold temps. being plugged it will retain water. water freezes and could be a potential hazard since it expands. don't know if it'd crack the drive since it could expand up. my self, i wanted it cleaned out on mine. really not to big a deal to clean it up (out). specially since you'll be looking (replacing) your impeller yearly imho. whlie yer doing the impeller. dig the crud out of that cavity. i used a long screw driver and a vaccum to suck the crud out. mine was packed in real good so it took some digging to get to the bottom. but ya do eventually. ream out the drain hole from the outside. it leads stright to the cavity that's got the crud in it. when your done it'll let the water drain out like it should when the drive is down. + it'll look like this when on the hose.
one more place for cooling water to exit the drive. that surly is good i'd think.
that's my 2 cent..
