1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 41Get this manual
Throttle Valve Synchronization With the engine idling in NEUTRAL, if loosening the carburetor lever adjustment screws results in better idle, improper synchronization of the throttle valves is indicated At idle, the throttle valves in all carburetors must be completely closedIf the carburetor linkage is misadjusted so one carburetor throttle plate is slightly open, it will result in poor quality idle1Remove the air silencer cover to observe the throttle valve action Loosen the throttle cam follower screw Push the throttle cam follower away from the throttle camThe throttle cam follower must not touch the throttle cam during this procedure ] 2
closed to be certain the throttle valves are closedPress downward on tab of the adjusting link to remove backlashTighten the adjusting screwMove the cam follower and check that the throttle shafts start to rotate at the same timeCam Follower Pickup