Yes that can be a reason too, as you know I am a paiggo owner as well, but now I dont ride it fast very often but back in those days when I bought it newly and ther were cuople of other 125 buddies we used to go on trip together (at a relatively fast speed) like harrappa, Rohtas Fort e.t.c.. I noticed this problem as well...
so instead of buying expensive Hi-Octance I used "STP OCTANE BOOSTER" its hardly 300Rs bottle for 30 liter petrol which means I can use it 3 time in paiggo.
And after adding STP to petrol... Speed = MIND Blowing, Acceration = YOU BET!!! (it is made from JET engine Fuel)
there are many other american brands as well but they are too expensive.
orignal Bottle looks like this I used to buy it from Makro , metro Big store to gaurantee its orignal.