All GPS-verified, same straight road, both way average speed measuring technique, same fuel and oil, carb always tuned speeds:
Derestricted: Variator boss, airbox/intake manifold, cdi cut, different roller weights (5,5gr).
A50 derestricted stock: 63 km/h
A50 derestricted Malossi multivar and #80 jet: 67 km/h
A50, Malossi multivar, drilled open airbox, #84 jet: 73 km/h and hit rev limiter (only capable of reaching this speed when tucked in)
A80, 72cc big bore kit, malossi multivar, drilled open airbox, #90 jet, camshaft stock: 73 km/h (need to tuck in slightly to reach top speed)
A80, 72cc big bore kit, malossi multivar, drilled open airbox, #90 jet, camshaft A9: 73 km/h (Basically almost reach this speed unless headwind is strong-ish)
All done on the same 2007 Kymco agility under the same circumstances.