you could have a pluged jet.. take it out squirt carb cleaner in it put it back and check for proper running.
With the screw all the way in shutting off fuel to that side the engine should be running terrible. It is getting fuel leaking from somewhere else or tip of screw is broken off/missing etc. etc. Ensure that starter rods are fully closed when they are supposed to be with choke off.ok so i just finished overhauling the carbs on a 96 gl 1500 that sat for about a year. also replaced fuel pump, fuel filter and rebuilt petcock. i got it all back together but i could tell it's just not quite right off idle. so i noticed while doing the idle drop procedure that turning the mixture screw on the right carb,all the way in or out has no screw effect at all. when i turn the mixture screw on the left carb it does what it's supposed to do. i know i need to backtrack/ any suggestions on what to look for would be helpful....thanks.
What you say is true. The fuel mixture is probably coming from the venturi as the throttle plate is too far open. I would suggest you try to idle it down to 700 or so then try again. All you have to lose is a little time.i had the idle set @ 800 rpm like the book says. the vacuummate digital sync gage had the carbs synced spot on. some how fuel was able to bypass the mixture screw being all the way turned in because it did not even flinch when i turned it all the way in