4.3L I/O Overheating/Wont Shift Into Gear

[Dave87]

Hi guys,

So I was driving my boat learning to wakeboard with some friends. All of a sudden loss of power. Boat wont go forwards or backwards. Also the motor is getting hot... Impeller was just changed two weeks ago.

When I put the motor in forwards i can feel resistance when i spin the propeller backwards .

When I put it in reverse i can feel resistance when I spin the propeller forwards.

Any help would be appreciated.

Thanks

 

[achris]

Sounds like a spun coupler. Put the drive in forward and have a friend turn the prop in reverse. You have a look at the back of the engine. You'll see the input shaft to the drive. While your friend is turning the prop, if that shaft is moving, your coupler is spun.. The only fix is to remove the drive, and pull the engine out...

Chris....

 

[Dave87]

Thanks for the response! This is sad news... I did try with the shifter in forwards and i spun the prop in reverse by hand and the shaft going in to the engine was spinning. Im supposed to do this with engine off right ? How complicated of a process is it to change the coupler myself ?

 

[Dave87]

also what causes this to happen ?

 

[Grub54891]

also what causes this to happen ?

Usually alignment will take out a coupler. Age can cause it also, but I'm running a 1985, And 2 1984 larsons that are just fine. If the transom and mounts/stringers are shot it makes them impossible to keep in alignment, and can be dangerous to you or your passengers.

 

[Dave87]

How does it get out of alignment ? could it be from running with a prop with to much pitch ? or running with a prop with a chip in it ?

 

[achris]

How does it get out of alignment ? could it be from running with a prop with to much pitch ? or running with a prop with a chip in it ?

Very unlikely. Overpropped will cause it to be overloaded, but those couplers are good to about 400hp, so your V6 isn't likely to hurt it. Out of alignment is the most common cause.

Before you drop the engine back in, check the mounts in the hull, and the transom for softness or sponginess. They're the most likely cause of alignment problems. When you do put the engine back in, align it properly, with the right tool! We hear of quite a few people 'aligning' the engine with the input shaft of the drive, or assuming because the drive slid in ok, it must be in alignment... Nothing could be further from the truth.

For direction on removing and installing the drive, and checking the alignment, with the right tool! have a look at my videos (link in my post signature)...

BTW, alignment is something that should be check at each annual service. It takes all of about 2 minutes, and can save plenty of grief....

Chris........

 

[Grub54891]

Just replaced a coupler in a 28 sea ray. The owner had just aligned it two weeks prior, using nothing other than a one inch wood dowel. Ge told me to get a dowel to re-align it. I used the proper tool. It was a good quarter inch low in the front.
The sad part was he drove up from Louisiana to vacation with his family. Got him repaired in one day, but at that point he never got to tour the Apostle islands. Alignment is the most critical thing for the coupler.

 

[Bondo]

Alignment is the most critical thing for the coupler.

Ayuh,...... 'n Grease,.... Grease is Very Important to coupler spline life,......

 

[Grub54891]

Ayuh,...... 'n Grease,.... Grease is Very Important to coupler spline life,......

Well yes. It was greased well by me! I should have known Bondo's any grease would show up! Lol

 

[Dave87]

Update....

I've removed the stern drive and the coupler is eaten up.

The engine mounts seem fine so I don't understand what's caused this..

I found some water inside the gimble housing . Could it be that ?

I'll post some pics later

 

[Dave87]

Also another question... how do I know which part to get? There seems to be two different kinds..

 

[Bt Doctur]

The engine mounts seem fine so I don't understand what's caused this..

Well, from what I can see the rear mounts may have collapsed

I found some water inside the gimble housing . Could it be that ?

Nope, that a main bellow leak, or a very high bilge water level t some point

 

[Dave87]

Bellows was changed two years ago I find it hard to believe that its already due to be changed.

I'm going to remove the engine tomorrow and see if I can see if its the rear mounts.

If its not the mounts do I run a big risk replacing the parts and them breaking again shortly after ?

 

[Dave87]

[No message]

 

[achris]

Bellows was changed two years ago I find it hard to believe that its already due to be changed....

Genuine or non-genuine? Bellows adhesive used? The person doing the job know what they were doing and what to look for?

Yes, bellows (new or replacement) should last longer than 2 years, but other factors can come into play, like a fishing line pulled across it. If the boat sits on a mooring and marine growth gets in, or if the drive is left in the UP position when the boat's on the trailer.

Chris.......

 

[Blueghost924]

Ah yep you have a leak in your U Joint Bellows. A lot of things can happen in 2 years even though you changed it out in that time frame. And looks like you have rust developing on the stern drive u joints. Trust me - I know from experience.

 

[Dave87]

And looks like you have rust developing on the stern drive u joints..

can I treat this rust and clean it off or am I looking at changing the stern drive U Joints ?

 

[Dave87]

Genuine or non-genuine? Bellows adhesive used? The person doing the job know what they were doing and what to look for?

Yes, bellows (new or replacement) should last longer than 2 years, but other factors can come into play, like a fishing line pulled across it. If the boat sits on a mooring and marine growth gets in, or if the drive is left in the UP position when the boat's on the trailer.

Chris.......

I did have it changed by a marine shop as it looks like an annoying job. Im not to sure I would want to tackle it myself. Which seems silly as I say this im removing the engine of the boat and changing the coupler.

What are your thoughts ? Should I suck it up and do it myself ?

And yes I did leave the motor up the last two winters while it was being stored .. So I guess thats the culprit.

 

[Dave87]

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