I could use some help and guidance on finding a service manual for a 1984 90 HP mercury outboard 6 cylinder engine. My brother in law just bought and I'm trying to help him out with checking everything out but would like a service manual to go by. I have heard it was called the tower of power. It is a 6 cylinder with s/n 6515958 if I have the right one. I appreciate any help to find a OEM manual if possible. Thanks