1972 65HP Johnson spits, sputters, and or misfires at mid range

my 1972 65HP johnson is misfiring at mid range roughly between 2000 and 3000 rpms. runs pretty good at idle and WOT and all other rpms in between(except for the range i stated above.) ive cleaned all the carbs, new plugs, new coils w/ wires, etc. could this be a tuning issue? i took it out yesterday, it ran good, i caught walleye, perch, and white bass like crazy. but im wondering why its misfiring in mid range. i started to mess with the idle speed mixture screws and the engine died on me, and i said hell with it cuz i wanted to get to fishing, it trolls real nice, but im thinking that i need to pull the throttle back to where the motor wants to cut out, and try to adjust the idle speed screws to keep it from stalling, and get it sound that way, could this be my problem at mid range with misfires????? also i can get it to troll at about 900 - 950 rpms real sound with no misfires and no stalling. i dont troll that slow anyways, i usually troll at my slowest around 1000 rpms, but i also wanted to mention that the troll does bounce a bit, 950 to 1050 rpms at times. any advice is great! thanks!