Slow Turning Starter.

[JIMMYJAMES]

Morning all

I have a problem with a slow turning starter which i'm trying to resolve. So far i have removed the starter, stripped and re greased all the gears and bearings and replaced the brush pack with very little improvement. Where do i go from here? The starter is like new internally with little or no wear on the gears, bearings and minimal scouring on the armature so i am loathed to replace it.

Any help would be appreciated.