The reason for upjetting to an 82 is to avoid running lean and damaging your engine, not to improve performance as such. Kymco advise it in their derestriction manual and it only takes half hour tops and a couple of bucks for the jet, so better to do it in my opinion, and Kymcos opinion for that matter. Better safe than sorry.
Your scoot may take a while to start 1st time after changing the jet bit dont worry, it will start up soon as the fuel flows again and fills the chamber in the carb. I thought I broke my scoot, wouldnt start up, had to jump it off my car, but once going that 1st time its been fine since.