I have a 1983 35hp Evinrude that starts with one turn of the key and runs
really good.
My problem is when I turn the ignition off the motor won't stop.
I have replaced the ignition switch and the starter solenoid but it still
won't stop when I turn the key off.
Is it possible it could be the CDI unit? Is there a way to test it?

Not sure what to do or where to look. Any help would be appreciated.

Thanks, Shane.