1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 93Get this manual
Brush Replacement IMPORTANT: Replace brushes that are pitted or worn to less than 14 in(6.4mm) in length1Install positive brushes into commutator end cap
Reassembly
1Lubricate helix threads and drive end cap bushing with SAE 10W oil2Install components onto armature shaft
11660 Positive (+) Terminal Long Brush Lead Push Lead Into Slot Insulating Washer Flat Washer Lock Washer Nut