Mercruiser 4.3 Alpha One won't go into Gear

[cringe]

I'm new to boating. Bought a 2002 Bayliner Capri, Mercruiser 4.3 V6 with Alpha One drive. It won't shift into gear now, forward or reverse. I've done a lot google searches so I hope this post makes sense. Don't assume I know what I'm talking about. You may want to "dumb down" your responses.

Boat was prep'ed for new season by a reputable boat mechanic back in April, used it maybe 20 hours since then. The last few times I've taken the boat out, I would shift into reverse and not hear the gear engaging, the prop would not spin. I'd move the throttle back to neutral and try again a few times and then the gear would engage. About a week later I hit a shallow spot in the lake, stainless steel prop drug about 5 seconds (I didn't know to shift into neutral, but do now!) on rocky bottom. Edges of prop are rough now. Next few times I took boat out, same behavior with the throttle to engage engine. Then last time out I was going about 15 mph and the gear disengaged and the engine rev'ed, coasted to a stop. Could not get gear to engage, had to get a tow back to boat lift.

I then ran engine on boat lift as a test. Water pump is working (water coming out). I guess that means the drive shafts are turning which means the coupler is maybe ok, but I don't know. I put throttle in reverse a few times and got nothing, not even any ripples in the water from the prop, then the prop did start turning last time I did reverse. I took cover off engine and the gear cables do move the that "lever" back and forward when I move the hand throttle forward and reverse.

This feels like the gear cable linkage is loose somewhere. Or might I have a spun hub? I will call a mechanic for a house call but just want an idea of what the problem is, maybe learn a few things too.

Also, can the prop blade edges be straightened and balanced? Or just buy a new prop? Mine is a Mercruiser Marine Vengeneance, 3 blades. Numbers on prop are 48 16316 19P and I don't know what those mean except the 19P seems to be the pitch. If I need a replacement prop, is there a better choice? Thanks!

 

[wahlejim]

Sounds like a new shift cable is needed at the very least. Pop the gear cover on your outdrive and make sure all of the teeth are in good shape. At worst, that is what needs fixing.

Does not sound like a spun hub. If there is minor damage on the prop, you can smooth it out with a file. If it needs to be straightened and balanced, search for a prop shop near you and get a quote. Typically re-working a prop like that will be about $125, give or take $25. Ideally if you wanted to buy new, they would let you test some out before you buy one.

Just a bit of warning about selecting a prop. Go through the prop section on this forum and you see guys on an endless chase fr ideal holeshot and top speed. If you are happy with your performance and the prop isn't spinning above wide open throttle recommended RPMs, you are in good shape.

 

[Rick Stephens]

If you are now on a trailer, you can do a few tests yourself. With motor off, put the shifter in forward, turn the prop Counter-ClockWise and it should lock into gear. Turning it CW it should ratchet and make clicking noise.

Put the shifter into reverse and turn the prop CW, it should lock into gear. It should ratchet and make exact same clicking noises as it did in test in forward gear when turned CCW in reverse.

If you want to know how the shift linkage should work, and you can make measurements to check everything, watch Chris's video on setting shift linkage here.

I run aluminum props, that way if I hit something I probably tear up the prop and not the gears or shafts in my outdrive. If you run where you can get into gravel or rocks, an aluminum prop will save you buying an outdrive. I would try something like a Solas Rubex 19 pitch 3 blade made for your Mercruiser and sold here on iBoats. Others will have other ideas of what is best, but that is a great place to start and if nothing else gives you a 19 pitch prop to carry as a spare if you get a little different prop to better your performance.

Rick

 

[cringe]

I did some more checking. When I move the hand throttle fwd and reverse, the shift linkage lever (where the shift and gear cables attach) above the engine does not move, not even 1 mm. The throttle on the other side of the engine moves just fine and the engine revs.The prop spins freely in any direction, no ratcheting, like the gear is stuck in neutral. So what's the prognosis now? Need some new cables? Doesn't "sound" expensive but hey I wouldn't know. Thanks guys.

 

[stonyloam]

Sounds like your throttle only button is depresses and stuck. When the button is pushed it disengages the shift linkage, but the throttle engages.

 

[Bondo]

Ayuh,... Sounds like the problem is within the controller itself,....

Which one were they puttin' in bayliners in '02,..??

 

[cringe]

OMG I think that was it, the 'throttle only' button was stuck in. I popped it out, pushed hand throttle fwd and the prop started turning. I'll have to take it for test drive soon. And when in fwd and engine off, the prop did ratchet and would not spin backwards so that test passed. My brain went from bad coupler to spun prop to bad shift cable to big dummy in the captain's chair. Thanks!

 

[Rick Stephens]

Now that's cool.

 

[stonyloam]

Yeah you might want to get some lube in there, a good oil, ( not WD40). Here is a link to the control manual https://drive.google.com/file/d/0B1...jlmLTg5NzktMjQyZDJhMGQ3YzQ1/view?pref=2&pli=1 you should be able to find yours.

 

[Baylinerchuck]

I love a happy ending

 

[cringe]

Update: It was a spun hub. Boat guy replaced mangled 3 blade SS prop with a 4 blade aluminum prop and new hub kit, and boat runs great. I know enough to do this repair myself next time. Boat gets out of the hole fast now, planes in about 5 seconds instead of 30 to 45. Top end speed is not as important to me since I pull kids behind the boat. Thanks all.