Velocity stack for a 24mm carburator on common Chinese 150cc scooters. Can be scaled to fit other carburators. Pictured is scaled down to 97% to fit the mouth of a PC20 carburator on a Honda Ruckus. Print in ABS or PET or Taulman. I soak tested an ABS stack in 87 octane unleaded overnight and it didn't seem to have any issues, so the short amount of time may come in contact with the stack is minimal. With PET or Taulman this shouldn't be an issue. I print at 100% infill at .3 layer height which gives me about 3 layers. I post process to remove striations but haven't tried post processing the PET or Nylon yet. With Nylon, use a raft and print on a piece of typing paper taped to the bed with painter's tape.