I bought a boat from an old man. He told me that he just had the motor gone through. When he gave the receipts for the work that been done to the motor it was done back in 2019 not this past spring. I got home and drained the oil from lower unit and there is some metal on the drain screw. Also the shift cable slips because the cap that locks the shift and throttle cable is missing. I solved that issue. Now when I tilt the outboard up and lock it in place has leak's out. I'm not certain but I don't think it's supposed to do that. My neighbor on the other seems to think otherwise and it's normal. My questions, is it normal for gas to leak from the carbs, and what years would a 20 inch lower unit fit my 1977 75Hp Stinger? When I was first researching parts for this motor I recalled that there were several years that would fit. Though I'm uncertain because I can no longer find the site with that information. Thank you for any help that anybody can give me.