I have a 1998 mercruiser 5.7 with a 2 barrel carb on it. This boat has been sitting for 6 years so i did all the normal stuff like draining gas,replacing plugs wires ect, rebuilt carb,fuel pump, cap and rotor. My problem is it has a rough and sometimes low idle boat fires up every time but if i try to give it some gas it will stall or try to stall but once i get it past 1200 rps its fine i had it in the water for 5 hours ran good except for the ilde issue i also noticed that the tachometer jumps around sometimes not sure if it has anything to do with it but what could be causing it to run like this?
