Pilot Screw turns? 04. 660 rhino stock carb

2004 660 rhino
stock engine, bigger stator, gibson exhaust

I have been having difficulty starting. parked in shop for 3 months.
first plug fouled easy.
then start slightly with backfires.
rpl fuel filter. Fresh fuel.
tore down carb, cleaned jets, passages, install,
started on choke, wont idle w/o choke, occasional backfire when rpm drops, low knock when idle drops low to stall.
pilot screw was 3 turns out (I think)

Does any one have any ideas?

two days til mud run!