I just bought a 1973 demcraft with a 1963 75hp evinrude 4 cyl. It starts and idles great but when you try to plane out it has alot of trouble getting over a certain spot between idle until it gets on plane and will barley get over an idle with the motor cover on. Once it sputters of the rough spot it planes out fine and will run about 25mph any help would be greatly appreciated.
