Wow, people are fed up with pod/velocity stack talk.
I'd just like to point out that, like you, everyone here has probably owned a bike that came with them, or attempted to use them because they look cool (thet do) , or someone handed down a set for free.
"It's not you, it's us".. I'd wager that 90% of the members here have chased erratic running conditions with pods/stacks only to eventually re-install a stock airbox with a better filter.
It's your turn to chase the dragon my friend, but you may only find snark and derision in the forum. There are some good older threads about some good starting points for jetting, but without a dyno and an exhaust gas analyzer, it's all trial and error.
you can probably get a lambda sensor for about $80. but honestly you'll still be fine just doing a plug chop on a good hill.
To be perfectly honest though... without engine mods or exhaust changes, those stacks really aren't worth running.
you won't see much if any power difference, and you'll lose some low end torque.
I actually did that. I bought an exhaust gas anyalizer with oxygen sensor.
You know what i found out?
They are not very accurate, and the sensor really blocks the exhaust flow.
They only give crude measurements.
Do not waste your money Just read the plugs.
It had 3 colored lights, LEAN,RICH and OK.
Not much help. You need to know HOW lean,HOW rich.