it's not bogus just only works for some people, depends on where you pinch the tube, how hard you pinch it how quickly you pinch it, the diameter of your fuel tube, how long your particular engine runs through fuel (all motors economy is different). The best way to adjust the LSN is to come from rich, so richen it up, and then lean it back again til it stops bogging down but don't confuse it with HSN rich as this will bog down if you increase throttle slowly whereas LSN won't. Example I pull the throttle fast it bogs and dies, I increase throttle slowly through the rev range, once it gets going it sings like a canary. LSN rich. I pull the throttle fast it dies at a certain point, pull the throttle slow it dies at the same point (roughly). HSN rich. Tuning these things can be difficult but once you 'know' your engine it's fairly easy. On my last car i had a single needle i knew once it pulled donuts it was too lean!! Of course that isn't accurate so i used heat smoke level etc. as well but it was a warning sign[8D]