Had to remove lower unit drain plugs on 2 outboards and they wouldn't budge. Tried loosening those plugs with practically all my might and they wouldn't open. I bought a manual impact driver on Amazon and it worked like magic. Try using one of those drivers the next time you have trouble opening those plugs. Every outboard motor owner should have one of those drivers . I purchased the shop manual for my Outboard and I'm slowly learning how to fix it myself. Fed up with incompetent overpriced marine mechanics.