Originally Posted by Roelof

One brand you should never trust of the constancy of the carburator is Novarossi. There are so many different low speed needles used that you never can say all carbs react the same, even when you buy a same engine there is a high chance there is someting different to the carburator. With starting a break in it is normal to set the idle a full turn higher because the high pinch on some engines will slow down the piston a lot and yes, Novarossi does set a decent rich starting tune on their carbs. Also after the break in there are some factors like mainly the fuel and a different exhaust (different back pressure) that requires a different tuning on the carb with which also the idle gap is affected

I did write it several times and now again that I have seen the bad side of the JQ video. A guy running that same OS carburator as JQ mentioned so he did set his idle to 0.5mm as advised in the JQ video. He did not get the LSN right with that idle gap but refused to change the idle at the right LSN setting.

So yes, with a given idle gap you can never tel if you do get the LSN tuning right. If it works, it works but will it be spot on? For anyone who can not tell if the LSN is set right it can be too rich or too lean on the LSN so it is wise to know and learn what the LSN does instead of tuning it to a given idle gap.
Of course you can start with a certain idle gap but at the end when you have the HSN and LSN tuned right you have to touch the idle screw to get the idle right and not the LSN.