Aaron---Biased needles, such as those used on most ZS carburetors, will
show wear mostly at their base. The light spring pressure causes this
part of the needle to rub against the jet, and will wear a flat spot, or
striations, on one side. Note that it takes a great any miles for this
to happen. Some tuners merely adjust the needles 'leaner' to partialy
make up for the larger annular area exposed by the worn needle. If you
want to know "how much" the needles in questions are worn, you can mic
them and compare to the Haynes needle chart for the B1AF needle. Note
that needles are shown in 1/8" increments. Striations are mostly just
visible, and pretty much unmeasurable. Flat spots that show the needle
to be worn more than .001 out of spec, are generally replaced. It would
be advisable to also check for an oval condition at the top of the jets,
if you want to make things as new.
Dick
'73
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