Whats up guys. i have a 1975 Johnson 70. The motor runs great when it is out of the water. in gear.. out of gear.. whatever. when i put in in the water it starts out fine then 10 to 30 mins. later it starts bogging badly and will hardly start. Once out of the water it runs fine again. I pulled the plugs and one seemed to have oily water on it..?? I gave it a compression test and all three cylinders are fine. One was a bit lower, but nothing drastic. I also pulled off the head and inspected the gasket which seemed to also be fine. any suggestions??
