full throttle Is full throttle,
If you rich @ bottom end @ full throttle and good at top end Making holes or slide changes wont do nothing
Those changes work at part throttle not full open throttle
Making a hole that stays uncovered at full open throttle will make the mix rich and you want lean at bottom end rpm not rich you say.
Tune for top end rpm because you don’t want to seize
so if rich at bottom rpm with full open throttle so be it,
Get screen and black cap filter and retune with that setup you may get better results over stock airbox filter, the black cap has a good inlet hole size for the 14.14 carburetor most times