... .Small spark,low noise BOSCH 91109 BSX 166 4-BS 166,dynastart carbon brush,starter carbon brush,carbon ... change color carbon brush‘s body, no ablation. (4) During the running, It can make the surface ... in Pounds/Brush = (Width x Thickness x 4 psi)Brush Holder Quartering:To insure that the best ... around the commutator. For a 4 pole machine, the spacing will be every 90 degrees. If the quartering is ...