Remove combustion air blower and take motor out of motor support housing.
Remove cover from motor housing.
Unsolder carbon brush from terminal tab. Bend up tongue on brush holder and take out spring and brush.
Dirty laminations should be cleaned with a clean cloth moistened with gasoline. If the commutator is burnt, replace the complete pole housing and armature.
Insert carbon brushes into brush holder, route contact pigtail through slot in brush holder to terminal tab and solder. Insert spring and bend tongue over.
Assemble motor, insert into motor support housing and reinstall combustion air blower.