Mercruiser doesn't want to 'lock in' to gear

tr@v1s

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Hey all. New to the site. Haven't been doing anything with boating for about 12 years. I used to be on iboats forum back then and messed around with little boats and old OMC outboards. I have just purchased a 1989 28' Harris Flotebote with a 3.0 mercruiser I/O (Alpha 1 Gen 1). Was not able to water test, but got to run it with muffs on and shift forward and reverses multiple times. Was able to get it around $3,000 under book price, and at a price we thought was a great deal, so we did it. That was last Friday evening. This is my first I/O.

Took the boat out last Saturday morning with the 20 year old son to test and make sure all was good before momma and the 21 year old daughter, 17 month old son, and 5 week old son joined us (yes, I have two generations of kids! lol). Everything went smooth. Motor ran great and seemed to move us across the lake at an expected speed (I certainly need to learn better how to set trim and all that stuff, but it was going nicely). We had about an hour to kill waiting on the rest of the family to show up to the dock, so the boy wanted to fish. we dropped anchor and unsuccessfully fished a few minutes and realized we were drifting toward the cove where there were lots of trees/stumps just below the surface. pulled anchor and put it in reverse and bumped right into a stump. Stopped the engine and tried to paddle out of the situation. Got where things looked clear, but could not get the prop to lock in to gear - just clicking.

Called for a tow. They broke down and had to bring seadoos for the tow after we'd waited a couple of hours. They looked at it in the water and though maybe busted u-joints. Got it to the trailer and took to their shop where they decided they didn't want to check it out until Tuesday. No communication or call backs from them Tuesday meant I was going to pick it up and check it out myself Tuesday night. I got it home and found that it seemed to engage fine if I pressed the shift linkage between the upper and lower units a little extra (whichever direction I was trying to shift). So I speculated that the shift cable was not adjusted correctly. Maybe I had stretched it or something when trying to shift out of gear when we hit the stump? I played with the lower shift cable last night and got it to where forward gear locks in pretty solid, but reverse with sometimes pop out (this is all tested motor not running and just turning prop opposite direct of shifted direction). I could never get to where both engaged equally well.

So, here's my questions:

1. Am I just not adjusting correctly?
2. Did I screw up my dog gear and need a rebuild?
3. Is there something else I'm completely missing?
4. Once I get this addressed, should I replace the stainless prop that was put on by the previous owner and go back to an aluminum prop?
5. Is it worth having a second out drive ready to go during boating season just to be able to swap out in event of breakdowns if you can pick one up fairly cheap?
 
Sorry, can’t help much with alpha drives - but I did just get done with a bravo shift rebuild - both cables, the shift plate, and the shift lever.

While the cables do require adjustment, my guess would be the fact a collision ‘broke’ yours leads me to believe there is more of a problem than an out of adjustment cable.

There are pluses and minuses to stainless props. If you already had an aluminum, I would probably advise you stick with it. But since you have a stainless, assuming it’s in good shape, probably better to just run with that. No reason you should need a spare outdrive. Eventually they wear out or break, but should not be a regular thing. every ten years or so with heavy use, and should last much longer if well maintained.

As far as getting this one fixed, there are some pretty good YouTube videos out there on adjusting the cables.
 
I think the cable is still not adjusted correctly. On an Alpha you would have either bent up the prop (if aluminum) or broken the plastic hub. Here is the Mercruiser guide for installing/adjusting the lower shift cable.
 

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Thanks guys. I went thru the adjustment process for both cables and got everything locking in in forward and reverse like they should manually (engine not running). Threw on the muffs and started her up. Didn't take long to find what "broke". I'm assuming it was on it's way out already as I was literally at an idle when the prop hit the stump. Motor coupler is toast. So, prepping to start that fun project and replace bellows and gimbal bearing while I'm in there and re-align motor with outdrive as I assume it has to be out of alignment to have completely destroyed the coupler.
 
Coupler is a tough one, as the engine has to come out - at least on my boat it did. I have a spare alpha coupler if you have any interest. But no idea of the condition. Going thru that much work, probably best to start with a new one?
 
Coupler is a tough one, as the engine has to come out - at least on my boat it did. I have a spare alpha coupler if you have any interest. But no idea of the condition. Going thru that much work, probably best to start with a new one?
I don't think it will be too bad. Can you send pictures of what you have?
 
Yeah, mine won’t work, looks like the 3.0 has the smaller flywheel.
 
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