Monobloc Initial Settings

Is just that, it should not have any effect until the engine is running. If you slacken it out then the slide should hang on the throttle cable, until it bottoms out, then you should be able to gentle screw the stop in until you feel the slide rise by the fact that there is now more slack in the throttle cable. If you can't find this point then ignore the throttle stop until the engine is running, (perhaps keeping it running on the throttle) then once it is modestly warm, adjust the pilot air (mixture) for fastest tickover, then readjust the throttle stop.

As you have lost the setting you will have to give it a good tickle and a bit of throttle to get it startrted . then screw in the throttle stop enough to keep running a bit fast .If the pilot screw is about 1 1/2 turns out thats a good starting point.slow the stop screw out to slow the tickover as much as possible the try the pilot in a turn  and the out the same to see which produces the fastest and even running ,then slow it down with the stop, a final 1/4 turn either way with the idle screw should give a tickover . If the carb is worn (sloppy slide) then all bets are off. You cant get it right with a cold motor or if the motor is running too fast as its then pulling fuel from the by pass or needle jet and wont respond to you. Its Assumed that the timing is right , plugs not fouled and fuel not too old .A little slack is needed in the cable Our Atlas is not starting well at present and a check revealed no slack on the choke cable not allowing the choke to work at small throttle positions  and a pilot jet too small or blocked with the pilot screw only a 1/4 turn out to compensate !. Another job!.

... a squirt of Bradex easystart will get it started and will normally continue to run while you get the idle settings right. Not to everyone's taste I know.....