Hi all I bought a 1984 wellcraft v20 fisherman a few months ago. Great first boat. It came with a 1988 yamaha 175 2 stroke that idles great but wont go over about 3100 rpm - about 20mph. The compression numbers aren't that great: 98, 98, 102, 98, 92, 85. When I bought it I couldn't get it to...