1970 evenrude 40 hp runs fine in idle and at half throttle but when open up to wot the motor hesitates and shakes back and forth for a few seconds and then takes off and runs fine not sure if this is carb problem, timing or maybe the fuel pump.
I feel for you sammons..... I am having the same problem with my mercury 90 hp, except after the shaking mine dies. I am going to use F R's advice and try to sync the carbs. I'll let you know what happens when its done.
