Spun prop or engine coupler?

Kchad917

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Aug 31, 2020
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5
So I had the family out on the water yesterday and I got the boat up on plane a few times ( 3.0 TKS with alpha one gen 2) when leaving from the sand bar I noticed a noise I have never heard before but it sounded like it was in the carb. I throttled the boat up doing about 42 and then backed it down going into a no wake zone. A buddy was a little ahead of me and I needed to tell him something. I ran the rpms up to about 2k and when it got there the boat fell on its face and the rpms shot up, I backed it down to about 1100 and continued. I then tryed to get it up to 2k and it did it again, this time the boat shut off when I shifted to neutral. It was like I was losing traction not like the carb is clogged, boat fired right back up and I got it to the dock and loaded it up where I gassed it to get it on the trailer and it didn’t do the problem, I had no smell of burning rubber or smoke and that weird noise went away. I’m praying I spun the prop hub but I also wouldn’t have luck if it wasn’t for bad luck. What do you guys think
 

Stinnett21

Chief Petty Officer
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Jun 24, 2012
Messages
611
Put a marking on the prop structure and on the rubber hub and see if they change after running it again. Any metal shavings below the coupler area?
 

Kchad917

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Aug 31, 2020
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I see no metal or rubber around the coupler, fired the boat and it’s turning ( not that it matters it does have a load on it) I pulled the prop. It’s a factory merc prop, brass piece with the splines doesn’t look like it spun in the plastic, And I can’t get the plastic out of the prop no matter how hard I try. There is a gray material in the prop that doesn’t looking like sand at all ( wet plastic dust?) this prop is pretty banged up from the original owner and I have a new one on order.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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51,327
draw a line across the prop and prop nut. if the prop hub is bad, the line across the nut will no longer line up with teh line on the prop.

you have been pulling the drive every year to check alignment, gimble and u-joints and grease the splines, correct?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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the other thing to do if that all checks out is pull the top cap and inspect the gears. if you toasted the gears, you trashed the drive.
 

Kchad917

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Aug 31, 2020
Messages
5
Scott, the boat was just done and complete in July, new motor and outdrive rebuild by a very good mechanic. I’m assuming the engine was aligned correctly so he wouldn’t have to fight the drive on. The only thing I never replaced was the prop, also I don’t know if this is anything but I felt some vibration in the wheel right before I took off and got on plane.
 

harringtondav

Commander
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May 26, 2018
Messages
2,476
Do the prop check first and keep your fingers crossed. If the hub spun a prop shop can press in a new hub....for about 1/3 or more of the cost of a new aluminum prop. It's not a bad idea to carry a spare prop...just in case.
 

Bondo

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Apr 17, 2002
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The only thing I never replaced was the prop, also I don’t know if this is anything but I felt some vibration in the wheel right before I took off and got on plane.

Ayuh,....... Welcome Aboard,....... Was there any weeds in the area when ya left the sandbar,..??

A prop fulla weeds acts like that,.....
 

Kchad917

Recruit
Joined
Aug 31, 2020
Messages
5
Thanks bondo, no weeds or anything. I’m also particular and push my boat out very deep before I lower the leg and fire the boat. Kinda has me going crazy. The prop is removed from the boat right now and I opened it up the hub is very stuck. There was a blackish Greyish material that was not sand behind the thrust washer, I have a new prop on order now. So I guess I’ll see what happens
 
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