Any advice on sudden loss of propulsion?

[jeffpr]

Hello,

Today we were cruising at 6 knots in our 2021 R5 Surf w/ 350 Volvo. We heard the engine start making a new high pitched buzz and propulsion stopped as if we'd shifted into neutral. Throttle advanced rpms but no propulsion in fwd or Rev. The buzz seems to come from rear of engine. I shut down, restarted, tried in and out of neutral /fwd/Rev, but no joy. Any ideas? Maybe we hit something and sheer pin failed ( though we didn't hear or feel anything)? Or gearbox?

Any ideas appreciated, thank you.

Jeff

[jhnmdahl]

Could be a lot of things, but I'd haul it in and have the outdrive inspected as soon as I could. Please keep us posted on what you find!

[jeffpr]

Thanks jhnmdahl. I took a look again today and here's more info (will talk to dealer tomorrow - of course this happens on the first summer weekend here in Seattle...)

Props look fine. The noise is coming from the back of the engine - I am no expert, but it seemed odd to me that I can see this spline thing at the rear, which wiggles but never turns regardless of neutral/fwd/reverse position of control lever (and EVC indicates it is going in/out of neutral). See photo.

Thanks again.

Jeff


https://1drv.ms/u/s!As1KqrZF3BnVxvYko5J ... Q?e=boWPRh

[bruceb58]

If that shaft is not spinning while your engine is running, the engine coupler on the flywheel failed.

[jeffpr]

Thanks Bruce, I bet you're right. Seems like an odd thing to fail under low load, maybe was not attached well and worked itself loose. I'll post what dealer finds.

[bruceb58]

Thanks Bruce, I bet you're right. Seems like an odd thing to fail under low load, maybe was not attached well and worked itself loose. I'll post what dealer finds.

So it doesn't turn while the engine is running?

The shaft is the input shaft from the outdrive itself. It slides into the coupler when the drive is attached. There is nothing to work loose.

The coupler is made out of aluminum. If it was not aligned correctly, that aluminum will shred itself fairly quickly.

[jeffpr]

Bruce gets the remote boat diagnostic award . Here's what the service tech said:

"We were out at your boat today, and found that the coupler on the rear of the engine has failed. It’s not engaging the driveshaft for the outdrive.
Our technician double checked and it’s unfortunately not an alignment issue."

Thanks again for the education.

Jeff

[bruceb58]

If the engine/drive was installed by Cobalt and they didn't do a good alignment, it will fail fast.

I bought my boat at the 3 year mark. First thing I did was pull the drive and check alignment. Alignment was WAY off. I am sure it was like that from the factory as I had to lower the front engine mounts. Unfortunately, previous owner never had it checked. I am sure there will be a new coupler in my future. Hopefully, I caught it early enough.

[dustinm]

Bruce gets the remote boat diagnostic award .

Jeff

He doesnt need a reward because he is the reward

[jeffpr]

An update - after 3 weeks, the engine coupler part should arrive soon.

The dealer said: "Your engine will need to be removed to make the repairs. it’s a very big complex job. We normally only preform this sort of work in the off season,..."

Of course I am concerned about finding the root cause of the failure at 32 hrs; and about future reliability of a pretty new boat as the engine must be removed and reinstalled. Somebody in another thread mentioned the word "lemon", with which I may concur. Our prior Cobalt had no issues.

[dustinm]

Sometimes you just get bad parts. Been happening forever and thats why there are warrantees

[bruceb58]

An update - after 3 weeks, the engine coupler part should arrive soon.

The dealer said: "Your engine will need to be removed to make the repairs. it’s a very big complex job. We normally only preform this sort of work in the off season,..."

Of course I am concerned about finding the root cause of the failure at 32 hrs; and about future reliability of a pretty new boat as the engine must be removed and reinstalled. Somebody in another thread mentioned the word "lemon", with which I may concur. Our prior Cobalt had no issues.

More than likely, the engine/drive wasn't aligned properly at the factory. You can have a failure very quickly since the coupler splines are aluminum.

[dustinm]

I'll just add that we've had a run of bad couplers from our suppliers.

[jeffpr]

Update: Dealer got the part in after three weeks, pulled the engine and installed it this week. I took it out for a test drive yesterday and while the coupler works fine, I noticed the steering was very heavy, especially turning to the right. The power steering fluid was very low and the cylinder to the left of the steering actuator was wet with fluid underneath, so a leak somwhere. Tech will check it out tomorrow...