Starter commutators usually don't have the mica undercut. It's necessary on generators because the mica will cause the carbon brushes to wear quickly. The sintered-copper brushes starters use are harder than the mica separators used between commutator bars, so there's no need for undercutting. Just do a shoeshine polish with some type of sandpaper or emery cloth that has non-conductive abrasive. The warning against using emery cloth on a commutator is because conductive material can embed itself in the grooves on a generator commutator and short out the windings. Not much danger of that on a starter, but I've got a roll of non-conductive roll abrasive for electrical work just to be safe.
I've assembled dozens of starter drives without an assist spring or a plastic washer, so don't get too concerned about not using them- - - -they work just fine without those pieces.
Jerry
Last edited by Hotrod Lincoln; 02/13/2014 6:43 PM.
