I like to set the Hi-speed needle for top RPM and then richen it a tad to drop RPM about 100-150 RPM. Then I set low-speed needle for smoothest idle. Sometimes you have to richen the Low-speed needle if transition is not good. Too lean a mixture on idle... it will bog out or quit, on quick acceleration. Too rich on idle the engine will load-up or run rough. This all has to be done with engine warmed up. Well ....thays my way!!! Capt,n[:-]