plug chops determined the 340 main ?
30 pilot ?
how many turns out on the airscrew gave you highest idle with the stock pilot that determined you needed to go leaner ?
https://www.blasterforum.com/threads/adjusting-your-airscrew-pilot-jet.51060/
I've tuned a bunch of blasters in all states of tune and various pipes, including an LRD, not one wanted anything besides the stock 32.5 pilot (high idle less than 2 turns out on airscrew)
unless your at some "in the clouds" elevation ?
leakdown tested ?
float height correct ?
fuel cap vent working ?
reeds good ?
don't count out an electrical situation, they like to show themselves under load and act just like a fuel problem.
TORS deleted ?
ground at coil to clean bare frame ?
unplug key and kill switch one at a time to count them out
unscrew plug cap, inspect up inside, if good cut 1/2" off wire and re-screw it back on
if burnt or jenky looking, replace with NGK screw on cap from auto store