Re: 1981 75HP Johnson
Sounds like link & sync -- if you have a manual, follow that procedure step by step. if you don't then at least make sure your carb butterflies are closed at idle and parallel throughout their range of motion, and the timer base moves smoothly without sticking. Also make sure the throttle cam hits the roller right on the mark.
Set the idle to 900 or 950 in neutral in the water.
If by "carbs have been cleaned" you mean anything other than "removed, disassembled and soaked overnight in carb cleaner," then you might need to have another go at 'em.
Check the "engine faq" section of iboats for how to fabricate a jet removal tool -- you've got 3 fixed jets and if the off-idle jets aren't clean can cause that symptom, particularly if using the choke makes it run.
