If your engine control looks like the pix above, it could be an old Morse, now apparently out-of-production.
Internally, the contol is a series of disks sandwiched together around a central splined shaft. The detents for neutral on the transmission bell crank and for idle on the throttle bell crank are accomplished by spring-loaded balls and holes. That is, steel balls about 1/4 in. dia are pushed into slightly undersize holes in the adjacent disk.
If your shifter is sloppy, you may have lost your balls.
If that's the case, it could be an easy fix.
Good Lord! I hope I didn't lose them completely!!!!! I've looked around and haven't seen them lying about. Maybe that's where the practice of "checking your package" comes from!
I think what I'll do is wait until haul out this winter and go ahead and replace the controls. Now wonder if I'm going to have to rely on someone else to connect new cables. I'd assume I would need new cables.