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Broken Driveshaft

There might be a set of weak drive shafts out there. I must have missed this thread when it happened, I had never seen a snapped shaft before! and we know of two now.
 
FYI I have a new 2021 Yamaha 275SD - the engine died and i had to have it taken to the shop. They just told me the driveshaft broke and both the driveshaft and the impeller need to be replaced. boat is brand new.
That's crazy. Take a quick look at the ring around where the impeller goes as well.
 
There might be a set of weak drive shafts out there. I must have missed this thread when it happened, I had never seen a snapped shaft before! and we know of two now.
N/A and SC 1.8s use different shafts, no?

--
 
You are right, the SVO engine appears to have its own part # for the shaft.
 
You are right, the SVO engine appears to have its own part # for the shaft.
Maybe the SVHO engine had a HO shaft in error? First time I heard of anything like this too.
 
I may have another... I am renting a 2021 AR 250 for the week in Cape Coral with 47 hrs. Was running about 35mph for an hour, slowed for a manatee zone, coming out of it, I throttled up immediately the Starboard engine made a terrible racket. Limped home on one engine, pulled the clean out port and impeller spins freely of the shaft and has no damage or evidence of anything being sucked in. Owners mechanic is coming this morning to look, didn’t want to touch it further, being a rental...
 
Bearing looks great, surprisingly. I believe when the shaft broke, it forced it up into the coupler. The splines on the shaft where it connects taper off, and I think it just kinda forced it together, hence why it took so much force to remove. New shaft, impeller, and bearing on order to be safe.

Veeduntek,

How did Barbara’s boat turn out? It doesn’t look like @Barbara has been around in a while, hope no news is good news.
 
It's been perfect since, no issues. Just saw her last week actually, they're taking the boat down to the Keys.

That’s great! Thanks for the follow up!!
 
I may have another... I am renting a 2021 AR 250 for the week in Cape Coral with 47 hrs. Was running about 35mph for an hour, slowed for a manatee zone, coming out of it, I throttled up immediately the Starboard engine made a terrible racket. Limped home on one engine, pulled the clean out port and impeller spins freely of the shaft and has no damage or evidence of anything being sucked in. Owners mechanic is coming this morning to look, didn’t want to touch it further, being a rental...
Did you ever find out what this was?

That sounds like something different to me. At least not a break AFT of the impeller.

If the break was aft, you shouldn't be able to spin the impeller/shaft through the clean out port without removing the spark plugs if I'm not mistaken.

If the break was forward of the impeller, then I think you would be able to spin it no problem but that would be extremely obvious because the shaft accessible through the clean out port would be very very loose.
 
Well guess I should have done some more googling, I have another one to add to the mix. Had a shaft break yesterday on a 2020 AR240 in the same spot as the original posters.
 
Well guess I should have done some more googling, I have another one to add to the mix. Had a shaft break yesterday on a 2020 AR240 in the same spot as the original posters.
YOU had a shaft break in the same spot????? Post up photos please!

I swear I saw a shaft break like this on FB in the last couple of months too - but searching FB sucks.
 
Well guess I should have done some more googling, I have another one to add to the mix. Had a shaft break yesterday on a 2020 AR240 in the same spot as the original posters.
Oh man....how you heard from Yamaha?

2020 and 2021 seem to be having the majority issues. If it is in fact a bad batch of driveshafts I wonder if we might expect to see some older models start to break as well if they have had shafts replaced (I just did on my 2014 for example)

Or it could be some sort of alignment issue in the newer models or housings that’s causing it but I would expect that to be more widespread.

either way, not good. Small positive note is that the shaft breaking is probably somehow saving the engine from being damaged.
 
Right at the beginning of boating season. Shoot I hope my 2021 212SE doesn’t experience this. No way to tell until it happens.
 
YOU had a shaft break in the same spot????? Post up photos please!

I swear I saw a shaft break like this on FB in the last couple of months too - but searching FB sucks.


I made a thread with some more photos but I will attach a couple here as well.
 

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Oh man....how you heard from Yamaha?

2020 and 2021 seem to be having the majority issues. If it is in fact a bad batch of driveshafts I wonder if we might expect to see some older models start to break as well if they have had shafts replaced (I just did on my 2014 for example)

Or it could be some sort of alignment issue in the newer models or housings that’s causing it but I would expect that to be more widespread.

either way, not good. Small positive note is that the shaft breaking is probably somehow saving the engine from being damaged.

I called my dealer on the water yesterday as I was making the one engine drive of shame 12 miles or so back to the launch. Initially it was a overheat alarm that caused me to shut it down, earliest appointment they had was May 7th. I called them back today when I pulled the pump and found the broken shaft, they said they would call me back if they want me to bring it in earlier to take a look and get parts ordered. I wanted them to order parts now so I didn’t have another couple weeks of waiting after I bring it in.
 
That is troubling for sure. The black melted stuff you mentioned in your other post is quite possibly the dampener between the driveshaft couplers. If the engines are misaligned or the engine mounts are loose, it could lead to excess rubbing between them and melting the coupler. There is a plastic cover over it so it doesnt sling stuff around the engine compartment. If you remove that you can inspect the couplers/dampener.

Dampener/Coupler
1618430841434.png

Cover
1618430878577.png
 
That is troubling for sure. The black melted stuff you mentioned in your other post is quite possibly the dampener between the driveshaft couplers. If the engines are misaligned or the engine mounts are loose, it could lead to excess rubbing between them and melting the coupler. There is a plastic cover over it so it doesnt sling stuff around the engine compartment. If you remove that you can inspect the couplers/dampener.

Dampener/Coupler
View attachment 146898

Cover
View attachment 146899

I popped the cover off yesterday, nothing noticeable externally, there actually wasn’t anything in the cover either. I didn’t start pulling anything apart, by the time I got the pump off today and ate some lunch it started raining, some more investigating will be done when it clears up.
 
I made a thread with some more photos but I will attach a couple here as well.
Looks a lot like this right? 2021 Yamaha 275SD. Yamaha not covering the DESTROYED ENGINE. 20k. How do we get these in front of Yamaha.
 

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Right at the beginning of boating season. Shoot I hope my 2021 212SE doesn’t experience this. No way to tell until it happens.
I’ve been out twice in my 212SE, and no issues so far. I’m still in the break-in stage at the next trip I get to open it up a little more. My top speed so far is 29 mph. I can’t imagine breaking a shaft.
 
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