Boat won't come out of gear sometimes unless you turn the key off

by Steve Oppel
(Louisville Ky)

I have a Johnson OMC outdrive and sometimes when I start to slow down the pull the shifter back to neutral it won't come out of gear. I then turn the boat off and restart it and it goes back to neutral. Any idea how I can fix this. It doesn't do it all the time but enough to be frustrating and unsafe.
Thanks,
Steve Oppel