Mercruiser 888 won't go forward

[nitedmn]

Got the boat back on the lake today after cleaning out the carb. Cruised around for a bit without any problems. Pulled up on a sandbar for a short period of time and everything was good. Started it back up, backed away from the shore and when I tried to go forward it when no where (engine revs but prop doesn't spin) . I pulled it back up on the sandbar and I'm hoping I can solve the problem here and enjoy the rest of my day.

If I shift into forward (with the engine off) . The I can only spin the prop forward. If I shift too reverse I can only spin the prop backwards. When in neutral it spins both ways. It acts like it's shifting but it won't go forward. Seems to work fine in reverse though.

 

[alldodge]

I' thinking your lower shift cable needs replacing. You could start by readjusting and see if you can get it going. It's right in the middle, just need to get a bit more to get it to finish going in gear. So far as what should happen in forward and reverse you good.

 

[Fishermark]

...engine revs but prop doesn't spin...

Sounds like a spun prop hub to me. Maybe a bad coupler or internal drive damage... but more than likely a bad prop hub. Do you have a spare prop to try?

 

[nitedmn]

Well... I left the tool kit at home so I wasn't going to fix it on the lake anyway. I wasn't far from the boat launch so driving there in reverse wasn't a huge deal. When I got there I couldn't get it back into neutral so it was clearly a shift cable problem. Before the problem started I also noticed shifting into neutral was a little difficult.

Once I got it home I was able to figure out how the shift cables work and I think I got it adjusted correctly. It now shifting cleaning into forward and reverse while on muffs.

 

[alldodge]

Once I got it home I was able to figure out how the shift cables work and I think I got it adjusted correctly. It now shifting cleaning into forward and reverse while on muffs.

Just a note if it does act up again: The shift interrupter is not used on muffs (no load on the prop), so it can work great on muffs and fail on the water.

 

[nitedmn]

Yep. I'm aware. That why I clarified that post by saying it was on muffs. The adjustment was made to the cable going to the control. Correct me if I'm wrong, but adjusting this shouldn't affect the shift interupter should it?

 

[alldodge]

Yep. I'm aware. That why I clarified that post by saying it was on muffs. The adjustment was made to the cable going to the control. Correct me if I'm wrong, but adjusting this shouldn't affect the shift interupter should it?

Agree, should have no effect