68' Johnson 9.5 Outboard weird RPM issue.

[oldboat1]

Sounds above like you are saying the tiller grip has a mind of it's own -- will rotate clockwise and stop the motor if untended. Is that happening?

 

[scatgo]

Do a cylinder drop test on it.

What is a cylinder drop test?

 

[racerone]

A simple drop test is you start this 2 cylinder motor.----Remove the top sparkplug wire and see what happens.----Install that top wire again and see how the motor responds.----Then repeat with the bottom cylinder.------A elegantly simple procedure that really explains what is happening !!