1986 Johnson GT150 (very) High idle

[GlastronMegatron]

Good afternoon all,

My Johnson GT150 is idling very high. It has been sitting a while and it is a new boat to me so I am not completely abreast of its history. I can start the engine with not much effort but when it kicks over it goes into a way high idle that sounds like its about to take off.

This high idle happens even when the butterfly valves in the carbs are completely in their shut position. Idle adjust handle and throttle are in their lowest setting as well.

Could this be a primer/choke solenoid issue? I tested the solenoid with a multimeter and its on the border line of being out of specs.

I am not super familiar with OMC/Johnson Evinrude Outboards and control boxes so is it possible I'm just being an idiot and have the choke permanently on or some idle setting too high?

Thanks in advance.

 

[racerone]

Check flywheel key.----If primer valve was open the motor would get too much fuel and would slow down.

 

[oldboat1]

throttle lever on control box in upright position? Could be a problem with shift cable. Go back to motor and check connections and linkages. Disconnect throttle remote cable, and operate at motor. If throttle operation is normal at motor, move to cable and box. (inner wire may be broken, or the thumb nut on the cable may be badly out of adjustment. hard to say from here.)

 

[James R]

Check that the advance retard lever is fully back on its idle position stop. It should be as that is linked to the throttle mechanism. However there could be something disconnected or a pivot coupling broken.