Yamaha aerox 2005 speed problem
So I have a tuned aerox from 2005, here is the setup.
Stage 6 Street Race 70cc
Exhaust pipes: Yasuni C16
Carburetor: Dellorto 19mm
Stage 6 Membrane (R/T Viton)
Greater intake
Crank: Polini Crankset (ForRace) - 10mm
Variator: Polini Highspeed
Clutch: Malossi Fly Clutch with Yellow Feathers
Rem: Athena drive belt gold series
Ignition: Motorforce racing
Air filter: Polini racing
Roller weights: 4.1g
Yellow Clutch Springs
Red Pressure Spring
But I have a problem: it only goes 74 km/h. The weird part is that I have upgraded the cylinder, carburetor, and exhaust, but it still goes the same speed. When I tightened the bolt on the left side in the variator, it did 78 km/h, with lower RPM and slightly worse acceleration. ChatGPT says it's due to light weights and a hard spring. I have no restrictions left.
Does anyone know how to fix this?.