Attributes . the thinner the diameter of the needle, the more fuel will be drawn. The thicker the diameter of the needle, the less fuel can be drawn. 10mm - 2.51. 20mm - 2.51. 30mm - 2.51. 40mm - 2.36. 50mm - 1.98. 60mm - 1.49. Original TM38 Flatslide . Names