Boat doesn't move under load.

[92rslt1]

I have a 1988 454 with bravo 1 and I was Pulling a tube today and all the sudden something let lose. It was like it was in neutral, rpm went Up and it stopped moving. The boat will move with no throttle but slips under any load. Any ideas? No abnormal noise, engages both reverse and drive fine with no throttle.

 

[Bt Doctur]

Re: Boat doesn't move under load.

engine coupler or prop hub.

 

[r.j.dawg]

Re: Boat doesn't move under load.

My first thought was a spun prop hub seeing as you have forward and reverse. Got a spare prop you can try?

 

[cr2k]

Re: Boat doesn't move under load.

Those are the only things that go out like that. Change the prop if it works you dodged a bullet. If not I see pulling the engine for a $300 part in your future.

 

[92rslt1]

Re: Boat doesn't move under load.

I'm thinking the coupler went. I can grab the prop and turn it when it's in gear and the shaft is moving with it still. I see the merc one is like 500 and there's a performance one for 400. Any reason to get the merc over the performance piece ? What else should I order as preventive maintenance?

 

[cr2k]

Re: Boat doesn't move under load.

Check on ebay or amazon. I got a $350 merc coupler for $179 NIB!

 

[MolsonCanadian]

Re: Boat doesn't move under load.

a spun hub will still feel "normal" when you turn it by hand. Mark a line on the hub and prop in the same spot. Go for a small ride and get it to "slip" again. Then check your mark, if its not lined up, you spun your hub.

 

[Don S]

Re: Boat doesn't move under load.

What else should I order as preventive maintenance?

An alignment bar and some spline grease.

 

[92rslt1]

Re: Boat doesn't move under load.

a spun hub will still feel "normal" when you turn it by hand. Mark a line on the hub and prop in the same spot. Go for a small ride and get it to "slip" again. Then check your mark, if its not lined up, you spun your hub.

Looks like your right the prop will move separate from the shaft of I force it. I am going to swap props and test

 

[92rslt1]

Re: Boat doesn't move under load.

Well I swapped props and it does the same thing. I'm not sure if the prop I put on it was good or not, I found it in the boat. It reaches plane and it's like it just goes into neutral. Seems to do it around 3500 rpm

 

[Don S]

Re: Boat doesn't move under load.

Doesn't sound the same to me, now you get to 3500 rpm before it "Goes to neutral" in the original post it wouldn't go over idle.
Neither couplers or props will deal with 3500 rpm if the rubber hub is spun. Slightly over idle is about it.

Would this spare prop run at 3000 rpm for a while?

 

[MolsonCanadian]

Re: Boat doesn't move under load.

When you swapped props, you also used a different hub right?

 

[92rslt1]

Re: Boat doesn't move under load.

Yea, the prop I took off was a quicksilver ss 23p 15 inch. That one would not do 3500 rpm. The prop I found is a 23p and around 13 5/8. It does look like the old props hub was shot, but this prop hub didn't look bad. I think it would run at 3500 for as long as I needed it too, any more and it slips out on me. It's like it just pops out of gear but no click or noises like it disengages.

 

[Eric 3.7LX Alpha 1]

Re: Boat doesn't move under load.

deleted

 

[Outsider]

Re: Boat doesn't move under load.

Mark the 'new' hub and test. I suspect you'll find it slips, too ...

 

[92rslt1]

Re: Boat doesn't move under load.

Ok, I found out the new prop is not slipping and I think it's actually popping out of gear. I had a friend watch off the back and you can tell the prop stops spinning. You can see in the wake behind it a spot where the water is unchurned.

Lower unit bad?

 

[r.j.dawg]

Re: Boat doesn't move under load.

Are you sure the prop is right for your 454 B1? I'm no expert, but I seem to think your prop should be around a 15" x 19p. Again, I'm no expert but your current prop just doesn't seem right to me.

 

[92rslt1]

Re: Boat doesn't move under load.

Yea, prop pitch is stock. Planes great and runs 60 mph at 5800 rpm with the quiksilver. Not sure with the other one.

Been reading and discovered the bravos have clutches apparently that can go bad. Still researching it tho.

 

[series60]

Re: Boat doesn't move under load.

Yea, prop pitch is stock. Planes great and runs 60 mph at 5800 rpm with the quiksilver.

I'd be real careful running the engine at 5800RPM!

 

[r.j.dawg]

Re: Boat doesn't move under load.

5800 RPM If I'm not mistaken, 4600 is the recomended max rpm for the carbed 454.