I have a 1975 4hp johnson motor, I just rebuilt the carb last week and replaced the water pump and now when I start it at idle it surges pretty crazy and will eventually die if I don't give it gas. The surging settles down as I give it a little gas. I can't really adjust the low speed needle at all either I don't think this would cause the problem though, I have set it 1 1/2 turns out from snug and I have played around with it a bit but its very hard to setup with the surging. I have tried pumping the bulb while it happens and does nothing at all, I don't think it has to do with the ignition as it smooths out very quickly as I raise the rpm a bit. I can't remember as I rebuilt it over a few days but I don't think I checked that the float was parallel with the housing when the carb is flipped upside down, I think I just left it to however the float came. Could this cause a surging problem if it isn't parallel? I will probobly take it off and double check either way but its starting to bug me as I am already into this motor much more then I want to be and it isn't running very smoothly yet.