I just finished a set of unmolested 70 carbs two weeks ago,100 % as new other than the caps had been removed by the original owner which he included.He had a note with them asking why he could only adjust the screws a minimal amount even tho the caps were off and also could not completely remove them.After removing the plugs for the angled screws and screws,they came out as they should.The main screw has about a 5/16" portion with no threads about 2/3 the length of the screw from the front and recessed about 1/3 the screw diameter,the angled screw went into that recess limiting travel and making the idle screw unremovable unless the angled screw was/is removed.