Johnson Evinrude Outboard Motors 1956-1970 1.5-40hp repair manual., Page 11Get this manual
PROPELLERS The cup has the effect of adding to the propeller pitchCupping usually will reduce full-throttle engine speed about 150 to 300 rpm below the same pitch propeller without cup to the bladeA propeller repair shop is able to increase or decrease the cup on the bladesThis change, as explained, will al ter engine rpm to meet specific operating demandsCups are rapidly becoming standard on propellersin order for cup to be the most effective, the cup should be completely concave (hollowed) and finished with sharp cornerIf the cup has any convex rounding, the effectiveness of the cup will be reducedRotation Propellers are manufactured as righthand rotation (RH), and as left-hand rotation (LH)The standard propeller for outboards is RH rotationA right-hand propeller can easily be identified by observing it as shown in the accompanying illustrationObserve how the blade slants from the lower left toward the upper rightThe left-hand propeller slants in the opposite direction, from upper left to lower right, as shownWhen the propeller is observed rotating from astern the boat, it will be rotating clockwise when the engine is in forward gearThe left-hand propeller will rotate counterclockwise1-5 FUEL SYSTEM With Built-in Fuel Tank All parts of the fuel system should be selected and installed to provide maximum