Was tooling along at around 85 to maybe 88 and I feel this vibration. I slow down and it doesn't get any better so I stop and after some guesswork… WTF! Has this happened to anyone else??? My marina said I flung a blade. I guess there is a lot of stress back there. [ATTACH=CONFIG]523799[/ATTACH][ATTACH=CONFIG]523800[/ATTACH][ATTACH=CONFIG]523801[/ATTACH]

Yep been there done that. Don't have a picture off hand but had the exact same symptoms and was a proud new owner of a 3.5 blade propeller. Btw I've seen your boat on 95 near northeast and it is definitely clean!

Did it mess up the outdrive -- at speed I'm wondering if that really bad balance may have screw up the alignment on the shaft/seals??

3pointstar

Yep. You got lucky if you didn't screw up anything else. My blade tore off over a couple of rotations and sliced up the lower (cavitation plate) beyond repair. Make sure you take a look at your other drive(s) for impact damage. If it doesn't feel right with a new prop installed, you may have bent the prop shaft. You will need to check the runout.

It could be that you're props were surfacing, I had a friend that had a 42 Fountain that had a very aggressive X dimension and would throw blades off his like this.

Yup, my buddy has a 38 ZR and he has knocked blades off. Different drives, different props but knocks them off. High X I think also.

Hard to tell, but enlarging it, it looks discolored , that would be where it was cracked if the area circled looks duller than the rest of the break..

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I was looking at that also and was wondering if it was a flaw in the metal. There are several spot that are dark if you look carefully.

Yes, I did check the other components out and they were untouched fortunately but we will check to see if the hub is bent also. Thanks

It's the nature of the beast. Unfortunately piercing or semi-surface piercing with a prop designed for full submersion doesn't work the greatest longevity wise. The constant loading and unloading of the blades causes fatigue, cracks, and ultimately failure. On high X boats inspecting props for small cracks every use is definitely necessary. I have a close friend with a newer 38' Fountain that has chunks missing from the bottom of both cav plates because it's lost so many prop blades from a previous owner. There's a reason why SSM and Herring props for 6s have so much material near the hub. Be conservative with trim if you can, and possibly look at spacing the drives down if it continues to haunt you.