i have a 72 50 johnson that when out of water and in apail the motor revs really good. But once you put it in the water the boat doesn't rev very high. it revs higher in reverse
Get a compression guage and test the compression on each cylinder should be within 10% of each other; also get an open air spark checker and check for a bright blue spark that will jump 7/16ths of an inch. You may be dropping a cylinder. Come back with what yu find.
