Timing before jetting.
Kits can't take hi stock timing you may have already damaged them.
Time with a light at 16-17 degrees on flywheeel with 16-18 thousands.
Bored carbs need the atomizer size for the size you bored them at. If not
You will never get them to run right.
14mm bings come with #222 atomizers
15mm bings come with #217 atomizers
If your "bored carbs" are between 14-15 then your kinda screwed.
If 14.5 mm then you need a hard to find #220 atomizer.
Me thinks you got a horrible #212A atomizer in your carbs.
#51slides suck too you need #24 slides
Stock exhaust needs stock carb, stock air box and stock air box
You made a missmatched set up for sure.
Kit needs a chamber pipe, hi flow filter, bigger jets, low timing