Looking to buy a 1999 Four Winns that has a Volvo penta on it. Everything looks good from the pictures but the only thing that concerns me is it sat in a slip all summer and the outdrive is covered in gunk. Before I go look at it, what concerns would you have with this? I will check all of the standard stuff but was wondering what kind of problems this accumulation could cause. And also how do you clean that stuff off lol