just set it so it sounds right? if it stalls, too low, if the clutch is grabbing, too high, and if you cant quite find the in between point, you need to adjust the lowspeed mixture, which is that tiny lil screw on the side of the carb. you set the idle slightly high and twiddle that screw til it peaks... then back off a touch. then readjust the idle and check... tweak if required.
learn NOT to rely on silly electronic gizmos that can send you off on tangents... these are not auto engines with sophisticated ecu and efi and all these other silly electronic things that can only be checked by plugging into a 10k+ machine and have to be kept within guidelines set by the EPA.
(yeah...real sophisticated...most of em still run basic led flash diagnostic systems... akin to the beeps your pc makes when somethings gone wrong... akin to using a pc in the early 70's... but its "bulletproof". they dont need to be user friendly, just to WORK.)
say, an oscilloscope is great, but my friends one kept producing a waveform he liked...he fiddled with a circuit for weeks, scope said it was working, but it wasnt...it ended up being the scope itself that was the problem.
same deal with his component tester. gave him the wrong pinout on an scr and it wasnt until i came and googled it for him that he realized why it kept emitting brown smoke... great on the majority of things but when you REALLY need it, its lets you down.
multimeters etc...unless you fork out big dollars they give spurious readings that can really drive you nuts. i refuse to use those stupid "auto-ranging" ones, they really are just a gimmick.