I have a 1977 55 seahorse. It starts up every time and goes into gear great. Two weeks ago at full throttle it started to bog down to about 10mph. It revs fine in neutral but when it is under load it bogs down. I bought a new prop cuz the hub was gone and that worked for two weeks. Then it did it again. I checked the timing, the carbs are clean and so is the fuel filter. The plugs are new and look fine. When I first put it in the water it does 30mph but soon as it heats up it bogs down again. I am out of ideas!
