How to speedup nouvo z / mio?

[traxxas-modifier]

hi guys

i have my fathers nouvo z now upgraded to 150cc and cams,
acceleration is quite ok but top speed is so slow!
well we have a test ride here, the nouvo z speedo shows 120kph
but GPS reading shows only 96kph

in fact xrm with 2backrides (habal-habal) i can hardly pass or we almost have
the same speed. well i can honestly say xrm stock 125 is faster than my nouvoz 150.

i believe the problem lies on the side area(belts pulleys,etc)
is it really possible to have 150kph on stock speedo nouvo z?

150kph will have a gps speed of 120kph.

HELP PLEASE...

 

[yanski]

u need to tune yung pangilid.. ask dsluchix.. she tune ups automatic(scooters)