This might be a little long but I really need some help with this. Let me first say I have built engines including autos and mowers but never an outboard. I bought the project boat and the 70 HP Evinrude had not been run for a least a year. The head was off the motor. The shop the previous owner had it at, said it needed rebuilt. The cylinder had a little scuffing like deposited ring or piston material. Looks pretty normal for a 1986 and even still has some cross hatch from the hone. The cylinder didnt appear to be heavily damaged I installed the head and did a compression test all plugs out. My gauge top 135 mid 95 lower 135. The compression readings at the shop today with a three plug machine, top 120 mid 85 lower 135. First shop said engine bad, has to be rebuilt. This based upon the scuffing. Second shop said probably can hone mid cyl and re-ring and lower was high because mid was low. Dont get that! Now, he wants $250 to pull apart to look and then tell me what it will take. Here are a few questions. Would de-carbing help or pulling the head and soak the rings with seafoam? Does the power head have to be removed to get the piston out to inspect the cyl walls? Cant I mic the walls and just re-ring.