Here's what I've accomplished so far in modifying my 2009 People 150, recently purchased as a brand-new leftover from a discontinued Kymco dealer.
NHRC carbon fiber exhaust. Fine fit and finish, nice exhaust note, manufacturing oils inside have to burn off during the first few rides, making rather foul odor. No big deal.
Cannisterectomy with plumbing removed and/or re-routed appropriately, allowing air intake mods.
Cone-shaped UNI air filter attached to NCY chromed metal air intake. Stock airbox modified by eliminating air tube from carb, Dremeled out lower front corner to admit larger air intake. New filter hidden inside stock airbox. Stock airbox intake opening enlarged about 50%
Carb rejetting (3rd variation) is close to spot-on now. Keihin carb, Original slow jet #35, now #40. Original main jet #110, now 117.5 Pilot air screw currently at 2 turns out
CDI swapped out for NCY derestricted model, allows modest increase in top RPM's assuming adequate fueling, as well as adequate air and exhaust flow.
Front tire replaced with Avon Viper Stryke 100/80-16F. Rear tire replaced with Michelin City Grip 110/80-16F. Mounted with direction of roptation reversed, as was customary with motorcycle tires before they actually came in "fronts and rears". This is 100% OK if tires are not radial. Improved handling, and larger front tire reduced speedo error from about 15% optimistic at all speeds to an even +4 MPH across the board. (GPS measured) Larger rear tire required slotting of holes in the rear hugger (sub-fender) to gain a bit of extra clearance for the tire. 2 minutes work with a Dremel. Larger circumference of rear tire should allow modest increase in to speed in engine power is adequate. (Rear tire alternative is 110/70, which should not require modification of hugger IF* tire profile ratios meet normal specs. However, there would be no top-speed increase with this tire.) 120's are definitely too wide on the People 150, as confirmed by other forum members.
Added Hepco Becker universal mount to the stock tail rack to allow quick-detach mounting of a H-B 40L topcase that I use on some of my Moto Guzzi motorcycles. (I use the scooter to do grocery, etc. runs from my truck camper)
I haul the scooter on a front-mounted VersaHaul rack made for scooters under 300#, modded to center the scooter between the headlights.
Next, I'm going to tackle the variator/clutch upgrades... Still shopping, and looking for advice.
Here's the rig in travel mode, going to the Annual Historic Artillery Match in Grayling Michigan. That's a whole 'nother story...