Ive got a 23hp Mudbuddy Mini, and I had a problem starting before last season. On the belt case, on either side of where the drive shaft comes out, there are 2 crackes. They both run down length-ways vertically along the corner/edge of the case. Because of this, water gets inside the case with the pulleys and belt. There is a drain screw in the bottom and I drain it everytime I can and have never drained any discolored water. It has all been crystal clear (No apparent rust?). Im going to weld the cracks, but is there any issues I can expect with the pulleys. My speeds have dropped considerably but I can blame it on the 3/4" missing off of my prop. Has anyone had this problem? Do I need to break it down and what should I look for? Thanks for the help.

The cracks are 4-6in each maybe.