1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 47Get this manual
2Loosen the upper carburetor lever adjusting screwnl 3Partially 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 backlash Tighten the adjusting screwMove lower throttle shaft and check that both throttle shafts start to rotate at the same timeCam Follower Pickup Pointl1Ql 1Connect throttle shaft amplifiersuch as the one shown, to the top carburetor throttle plate rw 2While on the camthe throttle cam, thethe center of the advancing lower embossed mark should align with
throttle cam follower as tip of the amplifier begins to moveTo 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