Can you "explain" a spun prop?

Drindin

Petty Officer 3rd Class
Joined
Oct 21, 2006
Messages
80
Yesterday, while fishing, I found myself in some pretty shallow water. The motor was running but I shut it off as soon I realized just how shallow. Anyways, earlier in the day, the motor ran fine. But after a buddy tried to crank the motor (in the mud) I started noticing drastic differences. If I VERY slowly increased the throttle, I would slowly increase speed. BUT, while doing that, if I tried to give it a DECENT bump in throttle, the motor would rev up, and the motor would suddenly act as if it shifted to neutral. If I stopped, put it in neutral, then back into FWD, the motor would propel us again.

Note: This was the maiden voyage for my "newer" boat...my old boat ran beautifully with this same motor. However, I changed the pitch of the motor several times yesterday, to see if i was a cavitation problem. No change.

So, can someone explain a "spun prop" or having a prop "re-hubbed"? I removed the prop expecting to see,maybe, stripped splines or something like that (a stripped out nut & bolt) but I can't see any "obvious" damage.
 

Drindin

Petty Officer 3rd Class
Joined
Oct 21, 2006
Messages
80
Re: Can you "explain" a spun prop?

So during the high revving, the prop shaft, is spinning like it's supposed to (according to the throttle), but the rubber "hub" begins spinning freely within the prop housing??
 

Outsider

Lieutenant Junior Grade
Joined
Apr 24, 2007
Messages
1,022
Re: Can you "explain" a spun prop?

That's pretty much it. And you probably can't make it slip by hand. I had one that I could finesse the rpm up to about 3000 before it would break loose. The only fix is to have the prop re-hubbed ... or buy a new one. :rolleyes:
 
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