I have a 77' Evenrude 70hp motor that boggs down under load. I tested the compression and all 3 cylinders were okay. I checked spark and all 3 were okay. I cleaned the carbs and removed the debris at the bottom of the bowls. But the motor still boggs when I give a little throttle. It will go at idol speed to about 3kts then will bogg down when I go faster. It runs fine with the fast idol lever and seems to run well at high RPMs. Only when I put it in gear and give a little gas it starts to bogg down. The first time I had this problem, I cleaned the carborators and it ran fine for about 2 months. This is the second time it happened. Even though I cleaned the carbs twice I still have the bogging problem. Any suggestions? 
