UPP intakes. No exceptions but OEM.
100% that boot is the issue. It will melt your motor down. Might as well do a compression test to see if there is even life left in it BEFORE you even attempt to fix the boot. Also, if you're kind of new to two strokes, do a little reading on tuning, reading plugs, how to tell if it's lean or rich, identifying an the symptoms different issues. It can get expensive just throwing parts at something with out ever knowing if it's the actual solution.