idle get stuck some times

just got my 1982 kz 750 running after 2 years of looking at it :laugh: well any ways down to the problem. Wll i idle at 1500 rpm but when i am rideing and go to come to a stop and hit the clutch and go right to N the idle will get stuck at 4100 rpm but if i down shit to first then hit the brakes till it gets under 4000 rpm it will go back to 1500. or even if i stop when it is 4100 rpm and let out the clutch sum like i am taking off it will drop pack down to 1500 rpm . i am not sure of the problem i did clean out the carbs . and i have my air/fuel set at 2 1/2 turns. runs good other then that

Have you looked at the mechanical ignition advance mechanism and see if it's working? It should be under a cover at the end of the crankshaft. Some light oil on the pivot areas should be all it needs.

Have you checked the intake ducts for leaks? How about the carb to intake manifold areas? all fasteners tight?

intake manifold is in good shape tight and no cracks intake ducts not so good at all (duck taped ) :lol: mechanical ignition advance all i did to it was clean a white build up off of it but that is all i did to it