1997 Johnson Evinrude "EU" 90 thru 115 90 CV Service Manual, P/N 507267, Page 39Get this manual
Throttle Valve Synchronization
1With the engine not running, remove the air silencer cover to observe the throttle valve action
2Loosen 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 procedure3Loosen the lower carburetor lever adjusting screw
4Partially open the throttle shafts and allow them to snap 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 time