Follow up: So, the kit had suggestions on what jet/needle settings to start with depending if the bike had an aftermarket exhaust and or airbox mod. I went with a 150main (stock is 145) and the needle in the 2nd from top position. I did not drill out the slide as suggested, too scared i guess.
First impression: The bike no longer pops and sputters when using the engines compression to slow down, this was and indication of a prior lean condition i believe. And I honestly can not say for certain if there was an improvement in throttle response, this was never a complaint before. But the backfiring is all but non-existant now and that was my biggest complaint.
The plug is such a PITA to remove otherwise i would pull it and check the condition, maybe some other day.
I was able to do the upgrade without removing the carb, only because i would have had to remove one of the crash bars, and i also couldn't figure out how to remove the choke cable carb side. The rubber diaphram was a [email protected]
# until i put some axle grease in the groove to keep the diaphram down until the screws could be put in. Beware, that black plastic cap is spring loaded and will pop up like a jack-in-the-box if you're not ready, like i was. The job probably took me about 3-4 hours, half of which was dealing with plastic and tank.