225 Slant needs a good idle. what rpms are you spinning?

my twin webers set up can idle as low as 550 in drive , usually have it around 650
takes of like bat out a hell ether setting , like the sound of it when it slow
Yes I don't know I can't keep mine running even ideling at 1000-1200 . Stalls and is so very inconsistent . Can't find a vacuum leak . All hoses are off and porttw plugged . Get no rpm Increase spraying carb cleaning around intake