need help with 1985 120 looper

i rebuilt this motor it is a 1985 the motor runs good after 1500 rpms but at idle it wont hardley run and will die if you push the chock in it will clean up and run better for a second or two the motor has new carb kits new electronics the carbs have been linked and sinked the motor has only run for about 8 hours on break in 25 to 1 oil mix could this be causing the bad idle or is it something else the plugs r black but not carboned up the motor acts like it is miss firing or loading up at idle or no wake rpms from 1500 on watch out this thing comes alive on my 16.5 nitro (max hp for boat) just need some help thanks alot