Motorcycle Questions? Ask a Mechanic.
Hi Ryan, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.Initially and almost always, vacuum feed is taken from the intake manifold. In some other instances, it would be a small port opening at the carb's output.
For test purposes, try plugging close this vacuum line.
Still, post back with clear / closeup pictures of this carb particularly the "...diapram choke that runs off of a vacume line..." Please click HERE.