I have recently picked up two 340 Olympics, a 74 and a 76. Both are in really good shape, however they were sitting for 12 years in a garage without being started or run. I have got them somewhat cleaned up, tank, new gas lines and other various things. The carbs seem to be fine and the fuel pumps are working but they are both having the same problem.......I can get them started by using the gas primer but they will not keep running. I am assuming that the problems are carb related but I thought I would ask for other opinions.
yeah it sounds like it is a prob with the carbs, but it really sounds like a prob with the pump, I know you said it was working, but I would first make sure its pumping enough fuel in, if you do discover that this is working fine, then the next thing i would check, is to make sure the floats in the carbs are not stuck, good luck