Originally Posted by Lille-bror

All that tuning...
Set the HSN on the rich side, and the lean the LSN until the engine say "ding ding ding". Turn the LSN a little out. Then you know where the LSN are too lean instead of wasting 1 hour of fine tune the low end 1/12 of a turn each time... Now, set the HSN so its just lean of the slow 2 stroke tune and fínally check the idle again. All you have to do the rest of the day, are a little in or out on the HSN if the engine starts to scream or go slow on the straight.
Now the carburator needles are in balance. If the idle starts to get a little rich, the HSN will also be a little rich and visa versa. Lean or richen the HSN an hour or two, and the idle will get perfect again.