NX125 idle trouble

I have a '89 Honda NX125 I am currently trying to get back up to par. I have bored the cylinder out .06 and replaced the rings and piston. The trouble I am having is getting the machine to idle. After it gets hot it will idle but hesitates to rev down. It seems like it is catching air but I cannot find any leaks. Have you any thoughts on what could be my problem? Also this carb has a jet on the manifold side, any idea where it should be set? Thanks

Since nobody has given me an answer, I will post my on. The retaining spring, (not the C clamp) on the throttle needle had moved up the tube enough to give the needle about a 1/4" of slop. This is what caused the poor idling and the slow to return to idle problem.