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Engine coupler

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timber mike

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I have a 1986 Bayliner Capri with a AQ131A engine and a 275 out drive. Last summer while we were using the boat, it felt like it had spun the prop. We recognized the issue as having spun a prop before. We replaced the prop. This didn't fix the problem. The mechanic said that the likely issue is the engine coupler. I did mark the prop to make sure the prop wasn't spun. That test showed the prop is fine. If anyone has 'spun' their engine coupler, does it feel the same as a spun prop? The mechanic wants $1,000 to do the repair. It doesn't make sense to spend $1,000 on a $1,000 boat. Is this something someone with reasonable mechanical skills can do 'shade tree'? Any and all advice welcomed.
 
The AQ131A engine is a piece of cake to remove..... especially if cantilever hung!
I'd be hard pressed if one took me longer than 1.5 hour to do, baring no severe corrosion issues.
The Flywheel Cover can remain attached to the transom shield, unless there is work to be done in this area.


Volvo-Penta-AQ131A-275D.jpg


Once the engine has been removed, the "drive coupler" is also a piece of cake to change.
These are an all steel Borg Warner style drive coupler.
It will look very similar to this Borg Warner drive coupler;
18-5661_0.jpg


I'd be very safe to suggest that these either work completely, or completely fail.... very much "unlike" a rubber hub drive coupler.



It would be a long shot, but once in a great while, a sliding sleeve may not completely stay engaged into the gear cup. This may be a more likely candidate!




But see my questions below!
  • How is the drive oil? It is by chance milky?
  • Have you recently switched to a different type of gear oil? (of which is actually engine oil for this drive)
  • Does the drive still propell the boat FWD?
  • Does the drive allow for reversing?
  • Have you tried a different propeller? (I highly recommend doing this)
  • Any vibrations?
IMO, the mechanic has not completed diagnostics on this. Since he has NOT...., how on earth can he give you a $1k quote on this?
I'd also bet you that he is thinking Mercruiser or OMC..... not Volvo Penta!
He may be the wrong guy for this!


1.5 hr to remove engine.
Drive Coupler ......... $100 (one on e-Bay as we speak for $65)
Time to install drive coupler...., and re-install engine........ 4 hr if he's very slow.
Do the math. :D

Yes..... this would be a very user friendly task for a mechanically inclined person IF this is the issue!

Remember, boats are never investments...... they are almost always expenses.
There is simply a cost in owning and operating one!

Point being.... if you need to spend $500/1,000 on this, it may be true..... you still have a $1k boat.
But if you use it 50 hours next season.......
$500/1,000 divided by 50 = $10/20/hr to own this boat.
What else can you do for $10/20/hr, and have this much enjoyment? (minus fuel and insurance, of course!)
And that is just engine run time.

Got any children? They love boating! :D

This is a good engine/drive..... and well worth repairing if the hull is any good!

,
 
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How is the drive oil? It is by chance milky? Oil is clear and clean.
Have you recently switched to a different type of gear oil? (of which is actually engine oil for this drive) No, but does need changing.
Does the drive still propell the boat FWD? Yes
Does the drive allow for reversing? Yes
Have you tried a different propeller? (I highly recommend doing this) this was the first thing done
Any vibrations? No, the boat runs at idle speed; however, when you try to get on a plane, it sounds like the engine becomes 'disengaged' with the out drive. It is kind of like a clutch slipping in a car. The engine speed increases, but the forward speed doesn't. If you back of the throttle, you can continue at a lower speed.

We do have kids. We even have one that joined the Coast Guard. We love boats in NC.
 
Like suggested...... although rare, the sliding sleeve may not be staying engaged into the gear cup.
Look at your drive oil!
Learn what type/weight it is.
See if you are getting water intrusion!


Mike, these single prop drives can run either hand propeller by simply switching which "driven gear" is used. There are 2 driven gears in this transmission.
All we do is swap sides for the vertical linkage piece, adjust for true "neutral", and adjust the the trim fin/torque tab to counter prop walk.

If you can test an oposite hand propeller, it may reveal something about the sliding sleeve and gear cup.
Try this, and see if this remains engaged.
This is why I asked you if it would propell the boat in Reverse..... although a tuff comparison!

.
 
I took your advice and took the boat out for testing, and ran it after I changed the out-drive oil. The boat starts well, idles well, and runs at both forward and reverse at slow speeds (1500 rpm) with no slipping. However, when you give it throttle, it accelerates fine to get on the plane until it reaches 2,500 rpm's. Then, the rpm's increase and the forward speed decreases. I can back off the throttle and the engine 'catches up'. It runs fine under 2,500 rpm's until it gets the load on the engine at about 1/2 way to getting on the plane and then something slips. As soon as you slow down, everything locks back up, and will push the boat fine. I have been unable to find a reverse angle prop.
 
Yep.... ditto!
You may have a prop that is way out of whack, and needs to be sent in for repair. Often it does not take much to cause one to act up.

I think that I suggested earlier that you try an oposite hand prop, swap the vertical linkage piece, re-adjust the exhaust outlet for prop torque trim, and give this a try.
This will place the load on the oposite "driven" gear, and most importatnly...... the oposite conical surface of the sliding sleeve and the oposite gear cup.


Which set of holes is the "set pin" inserted into? FWD, Center or AFT-most position?
 
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