Low idling/dying at traffic lights.

[DanDaMan]

check hoses that look like vacume ports for EPA and repair or plug , sucking air after the carb will let bike run but will be rough/die at idle

the rubber bit that bolts the carb to the motor (that EPA ports also are located in) can leak (cracks/gaps) and cause exactly your symptoms , can be as easy a fix as ducktape to cover cracks (short term) , and high temp engine gasket silicon for longer and more heat sensitive area's

so be4 you go spinning adjustment screws and tearing down carb , have a look at rubber bit (intake manifold) and see if you suckin air