what brand is the engine they all have a little different needle settings, BTW the cleaner the carb is the more responsive it will become to adjustments, if the engine has sit for a while the carb can get fouled by gum deposits making for sluggish results when your trying to get it tuned properly.

another thing is to (sure to be bashed for this) get a tachometer, http://www3.towerhobbies.com/cgi-bin...?&I=LXPT31&P=0 its helpfull for tuning a 4st engine, if you haven't worked with one before, finding the low and high end of the RPM range is important when tuning a 4st and can be tricky if you haven't done it before