i'd drill the stock pilot out one size at a time, assuming you're using a full set of pindrills.
these circuits are so small that even one bit size is a large percentage change in fuel flow and the shape of the entry and exit of the jet matters also.
drill extremely carefully and slowly; don't push it though.
only make one change at a time and only on one circuit at a time.
if you've got a mechanic buddy ask if you can use his exhaust gas analyzer; it makes narrowing the tune down quickly much less of a chore.
or you could weld a 16x1.25 (iirc) nut on your headpipe, burn a hole, and screw a $10 universal oxygen sensor in it and read it w/ a dvom.
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