Carb Jet Kits and rebuild

Have any of you guys ran the Dyno Jet carb kits? Not even sure I need to do anything, runs good for the most part but some slight hesitatation and the occasional back fire on deceleration. Idles a bit rough when cold.

Cleaned carb with sea foam last night and haven't had a chance to run it. (I should also mention just did valve lash on intake and exhaust)

Changed spark plug and plug was white at the contacts but some carbon build up around the threads.

I have K&N air filter but stock pipe and everything else. Waiting for my JBS sheave so I have it tore apart and can't stop tweaking and cleaning while I wait. haha

Oh yah did the spring mod last night to it also. Cut 4 coils. That should help with throttle response and hestitation off the line.