Lost reverse and neutral

Just put my 1996 Glastron GX 185 FS in the water yesterday. Started right up and ran great. But as I was bringing it to the dock after running it for about a half hour, I went to shift into reverse and it just stayed in forward. No neutral either. If I increase the throttle in reverse, it just increases the speed forward. I've never had this happen before. Does it sound like a transmission problem or a throttle problem? Something happened while I had the boat out running around because when I put it in the water and started it up at the dock, it was in neutral and it was just fine. If anyone has any thoughts, I would greatly appreciate it.

Sorry, I forgot to mention the boat has a 4.3 Mercruiser I/O

Re: Lost reverse and neutral

Sounds like a shift cable problem.
Disconnect the outdrive shift cable at the engine, start the enigne (on muffs if out of the water) and see if you can manually shift the drive by moving the cable by hand.

Re: Lost reverse and neutral

Thanks Don. I'm pretty new to tinkering but I assume the shift cable connects at the rear of the engine. I have to crawl in through a hatch. I'm not sure I want to be down in the engine compartment while the engine is running. Before I head down there, what kind of tools should I bring with to disconnect?