1996 Bayliner 4.3L Coupler replacement

[MLofsted]

Hello...
I think I need to replace the engine coupler in my 1996 Bayliner 1850 4.3L Mercruiser with Alpha 1 gen II sterndrive.
I know I will need to remove the motor and sterndrive. Sterndrive not an issue. I have read some posts that there is a link somewhere where I can download a service manual to do the removal project. I just need to know what to undo and in what order to do it. The posts say to go to the "adults only" icon but I can't find that icon anywhere.
Any help or suggestions to help me remove my engine? Thanks for reading this.

MLofsted

 

[Bondo]

Re: 1996 Bayliner 4.3L Coupler replacement

Hello...
I think I need to replace the engine coupler in my 1996 Bayliner 1850 4.3L Mercruiser with Alpha 1 gen II sterndrive.
I know I will need to remove the motor and sterndrive. Sterndrive not an issue. I have read some posts that there is a link somewhere where I can download a service manual to do the removal project. I just need to know what to undo and in what order to do it. The posts say to go to the "adults only" icon but I can't find that icon anywhere.
Any help or suggestions to help me remove my engine? Thanks for reading this.

MLofsted

Ayuh,.... Welcome Aboard,.... How'd ya figure it needs a Coupler,..??

Click here for the Adults Only section,...

It's found at the top of All the I/O forums,...

Pull the drive 1st, then the motor,...
Align the motor, before ya put the drive back on,...

Good Luck,...

 

[MLofsted]

Re: 1996 Bayliner 4.3L Coupler replacement

Ayuh,.... Welcome Aboard,.... How'd ya figure it needs a Coupler,..??

Click here for the Adults Only section,...

It's found at the top of All the I/O forums,...

Pull the drive 1st, then the motor,...
Align the motor, before ya put the drive back on,...

Good Luck,...

Bond-o....Hi, good question. The reason (and I could be totally wrong) I believe I need to replace the coupler is this:
Twice now when I've been out in the boat, when I try to get on plane, the boat motor will rev high and I have to reduce the throttle. I give it another go, and the boat starts to get up, then the motor revs again and again. I've been able to get going again after tilting the outdrive all the way up for a few minutes, then dropping it back down, then the boat will run great and I can now get up on plane. Like I said this has happened twice now this summer. I've checked the prop coupler and it looks Ok to me. I bought the boat last year, and have had some work done last summer. Gimble bearing was making a lot of noise, so had that replaced, and now runs much more quiet. I also had new shift cables installed along with new bellows, etc. The person I bought the boat from had just bought a new prop and prop kit which included the new prop coupler. What else could be causing the boat to rev high and not go anywhere. The fact that it eventually does get going worries me, because I don't know if a coupler issue could be intermittent or not. I'm starting to think that the motor mounts are worn or loose or something that is causing the motor to shift (maybe why gimble went bad), and tilting the outdrive up all the way somehow allows the coupler to work?? I just don't know for sure. What do you think? Oh, BTW...the original prop from the factory was a 13 7/8" X23. The prop on it now is 14 1/4 X21. I also have a 14.5 X 19. I don't see much difference in performance with either prop. Any help or opinion is greatly appreciated...MLostedt

 

[Bondo]

Re: 1996 Bayliner 4.3L Coupler replacement

Bond-o....Hi, good question. The reason (and I could be totally wrong) I believe I need to replace the coupler is this:
Twice now when I've been out in the boat, when I try to get on plane, the boat motor will rev high and I have to reduce the throttle. I give it another go, and the boat starts to get up, then the motor revs again and again. I've been able to get going again after tilting the outdrive all the way up for a few minutes, then dropping it back down, then the boat will run great and I can now get up on plane. Like I said this has happened twice now this summer. I've checked the prop coupler and it looks Ok to me. I bought the boat last year, and have had some work done last summer. Gimble bearing was making a lot of noise, so had that replaced, and now runs much more quiet. I also had new shift cables installed along with new bellows, etc. The person I bought the boat from had just bought a new prop and prop kit which included the new prop coupler. What else could be causing the boat to rev high and not go anywhere. The fact that it eventually does get going worries me, because I don't know if a coupler issue could be intermittent or not. I'm starting to think that the motor mounts are worn or loose or something that is causing the motor to shift (maybe why gimble went bad), and tilting the outdrive up all the way somehow allows the coupler to work?? I just don't know for sure. What do you think? Oh, BTW...the original prop from the factory was a 13 7/8" X23. The prop on it now is 14 1/4 X21. I also have a 14.5 X 19. I don't see much difference in performance with either prop. Any help or opinion is greatly appreciated...MLostedt

Ayuh,.... With that story, I really Really doubt it's the coupler,....

When it Goes, the boat Don't,...

Are ya boatin' in Weedy waters,..??

Do ya know how to clear the prop, when Weeded up,..??

Generally, shiftin' to the opposite direction, 'n abit of throttle, then back to yer direction of travel clears things up Nicely,...

 

[makonnen]

Re: 1996 Bayliner 4.3L Coupler replacement

Agreeing with Bond-o here, if you Google what a coupler looks like you'll see for yourself that it "shouldn't" do that just by the way its designed. If it were to happen ... the boat revs high and coupler slips, you figure you'd see some smoke or smell burning rubber at the very least. BTW you should be able to see the coupler ...

On the other hand, a slipping prop hub seems more likely. I realize you said it has a new prop / hub etc ../ but you just got the boat, who knows what the real story is? Also something else to think about, you can't always look at a prop hub to diagnose it.

 

[hivoltg]

Re: 1996 Bayliner 4.3L Coupler replacement

Mark that prop and hub with a perm marker or nail polish and see if it moves after a test run. Also make sure you have a good thrust washer behind that prop. If the washer has hub circle scratches into it...that prop is slipping.

 

[littlebookworm]

Re: 1996 Bayliner 4.3L Coupler replacement

Bottom line: When a coupler goes/tears, it uncoupples, period. The engine will rev and the boat won't move. Since the boat is moving, I have to agree with Bond-o and makonnen. It's probably a bad prop hub which is allowing the prop to slip. Pulling the prop and changing it is a great deal easier and cheaper than pulling an engine. Check carefully before you proceed with pulling the engine. Hy

 

[alldodge]

Re: 1996 Bayliner 4.3L Coupler replacement

I've been able to get going again after tilting the outdrive all the way up for a few minutes, then dropping it back down, then the boat will run great and I can now get up on plane.

Like I said this has happened twice now this summer.

(maybe why gimble went bad), and tilting the outdrive up all the way somehow allows the coupler to work??

I don't see this as a coupler or prop hub, I'm thinking along the line of incorrect trimming

When you take off the first time do you drop the drive all the way down?

 

[alldodge]

Re: 1996 Bayliner 4.3L Coupler replacement

Alright old guy here just thought of something else.
Does the boat seem to be out of gear, and when you move the drive up and down is there a clunk that goes on and now it will move?????

 

[MLofsted]

Re: 1996 Bayliner 4.3L Coupler replacement

I don't see this as a coupler or prop hub, I'm thinking along the line of incorrect trimming

When you take off the first time do you drop the drive all the way down?

Yes, the trim is all the way down

 

[MLofsted]

Re: 1996 Bayliner 4.3L Coupler replacement

Alright old guy here just thought of something else.
Does the boat seem to be out of gear, and when you move the drive up and down is there a clunk that goes on and now it will move?????

Yes, it seems like it slips out of gear. That's what I mean when I say revs up. But there is no clunk or any type of noise when I raise the outdrive.

 

[Bondo]

Re: 1996 Bayliner 4.3L Coupler replacement

Yes, it seems like it slips out of gear. That's what I mean when I say revs up. But there is no clunk or any type of noise when I raise the outdrive.

Ayuh,... Ya never said,.... Are ya boatin' in Weedy waters,..??

 

[MLofsted]

Re: 1996 Bayliner 4.3L Coupler replacement

Ayuh,.... With that story, I really Really doubt it's the coupler,....

When it Goes, the boat Don't,...

Are ya boatin' in Weedy waters,..??

Do ya know how to clear the prop, when Weeded up,..??

Generally, shiftin' to the opposite direction, 'n abit of throttle, then back to yer direction of travel clears things up Nicely,...

I am sure glad to hear this! I didn't relish the idea of pulling the motor. I wasn't sure if the motor coupler could be intermittent. Now after looking at pictures of these couplers, I can see that it either works or don't.
To answer your questions, YES I am in weedy waters (Calif Delta). And my way of clearing weeds off the prop is by reversing the engine for a bit. The last time this happened, I did have a few bits of weed on the prop, and when I lifted it up, I removed them by hand and the boat ran fine. Just can't imaging that a few bits of weeds would do that.

Really appreciate all the great responses from all of you. I will mark the prop hub and check to make sure the thrust washer is correct, just to see if the hub is slipping. It looks good but I do see some fine cracks at each corner of the prop coupler, so maybe it is slipping somehow.

I'll be sure to let you all know how this turns out. Great boating to you all!!