I have a 1987 70hp bigfoot mercury. I know it has been known for water intrusion. I had a backfiring issue and did a compression check the bottom 2 cylinders are 115 the top is 50. I thought it was about time for a rebuild. The thing that has been kicking my butt is I can't for the life of me get the power head off. I removed the six bolts and looked for a hidden bolt but can't find it. Can anyone help me out?