1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 19Get this manual
34 While aligning splines, place uicksilver propeller and tab washer on propeller shaftTo prevent propeller from rotating, place flat block of wood betwe en the anti-ventilation plate and the propellerThre ad propeller nut on propeller shaftTighten securely with wrench [minimum of 55 lbft(75.0 m) of torque] and bend tab washer to secure propeller nutAfter first use, bend the tab straight, re-tighten propeller nut [minimum of 55 lbft(74.6 m) of torque] and again bend tab washer to secure nutC heck propeller periodically for tightness
Corrosion Control Anode
The trim tab on the ge ar case is corrosion control anode and Models which have the longer type of transom brackets will have second anode installedAn anode helps protect the outboard against galvanic corrosion by sacrificing its metal to be slowly eroded inste ad of the outboard metals6