1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 49Get this manual
2Loosen the upper carburetor lever adjusting screwPartially rotate the throttle shaft open and allow it to quickly snap to the closed position to be certain the throttle valve is closed in the throttle borePress lightly on tab of the adjusting link to remove backlashTighten the adjusting screwMove lower throttle shaft and check that both throttle shafts start to rotate at the same timeCam Follower Pickup Pointr;Q1 1Connect throttle shaft amplifiersuch as the one shown, to the top carburetor throttle plate1,1l 2While advancing the throttle cam, the lower embossed mark on the cam should align with the center of the throttle cam follower as tip of the amplifier begins to movef121 3To adjust, align the lower embossed mark on the throttle cam with center of the cam follower (follower screw should still be loose)Allow the throttle spring to close the throttle valvesWhile pressing on the cam follower lever, hold the cam follower against lower mark on the throttle cam and tighten the screwRecheck that the throttle valves begin to rotate as the embossed mark aligns with center of the cam followerCam Follower Pickup Timing 1Connect timing light to No.1 cylinder spark plug lead2Advance the throttle by moving the throttle control lever until tip of the amplifier begins to moveRemove the amplifier but do not move the throttle control lever3Start the engine and observe spark advance with timing lightThe proper pickup timing is indicated in chart6626