I have a 2000 Sea ray 180 with a Mercruiser 3.0L motor. I just changed the fuel pump to a Carter model number m60337. fuel pressure is reading 4.5-5.5 psi when i try to start it. on the water the boat runs good above 1000 rpm, no hesitation Just gets up and goes and sounds good . but under 1000 rpms idles like crap. I tried to set the idle mixture and idle screws under a load in the water but once going below 1000 rpm the motor does want to run very well. a couple times the motor died and in order to start it i have to go full throttle as if it's flooded. most of the times even if i used the key to shutdown motor I have the same issue, I have to go to full throttle to restsart. the funny thing is when I brought it home and put it on the ears to flush the motor it was starting right up in idle. still rough idle but would start. after what I have read. think I need to rebuild carb. or get a new one.*

just wanted some input before I go down that road in case it might be another issue I am missing. thanks in advance for the help