[imported_lunytune]

are all 4 wheels spinning? check your wheel hexes and the pin that goes through the hex nut. it could be possible the wheels are spinning but slipping in the hex nut, not giving you enough power to the wheels to give you top speed, also are your tires glued to the rims??

also check that all 4 wheels are firmly on the ground and the chassis is not bent in any way that allows a wheel to be slightly raised of the ground, causing less traction

I don't see how it is possible for your tires to spin on the surface and the truck not move quickly? if only one end spins maybe the other is locking up and causing the problem?

This is a problem I think that would need to be seen in person and not discussed? *L*