what causes butterflies not to fully shut in barrell ,can still see down back of butterfly through progressoin holes or is this norm
cheers
richard

Idle stop screw wound in, not enough slack in cables, not enough return travel on pedal etc.

They will be partially open, the engine needs some air at idle!

David

or a bent spindle, or (most likely) a previous amateur dismantling & reassembly of the throttle spindle & butterflies (really best left alone if possible)
Bob