Spun Prop....??

[capecodder116]

1984 Tiara with 260 Mercusier engine, closed cooling system, Alpha One drive.

Yesterday we were crusing at 2800 R.P.M.'S when all of a sudden the engine rev's went up and the boat lost MPH. Immediately pulled the throttle back to neutral.

Boat would move forward at 1000 R.P.M. but no more then 1000 R.P.M. otherwise the rev's would just come up. Made it back to the dock pulled the boat and here are my findings.

Put the drive in forward and turning the prop CLOCKWISE, you hear a light click, click, click (I think that's normal). Trying to turn the prop COUNTER CLOCKWISE, prop turns maybe 2 or 3 inches at most and then will not turn any further. I put a lot of pressure into turning it COUNTER CLOCKWISE, but not all my strength into it.

I was hoping I only spun the hub on the prop so I pulled the prop but everything looks intact. Anybody got any thoughts...??

 

[Bt Doctur]

is it a rubber hub or flo-torq hub. did you check the oil level in the drive

 

[Fishermark]

Pretty much has to be either a spun prop hub or coupler. Do you see any residue around the coupler inside the boat? Smell any bunt rubber? On the props I have seen with a spun hub there is very little damage visible. You can always make a mark on the prop and the hub and try it on the water again. See if the marks are still lined up.

 

[Bt Doctur]

prop turns maybe 2 or 3 inches at most and then will not turn any further

could be a prop hub if its the rubber one, flo-torq would just shatter.but the turns for 3 inches could mean gears or driveshaft too.

 

[stonyloam]

Sounds like a coupler. Broken vertical driveshaft or gears, it would not move, and would overheat right away, and the prop would turn CCW. Prop, you would see some damage to the rubber. If there is no burnt rubber, you could have taken out the coupler splines. Good luck.

 

[capecodder116]

Thanks for the responses.... So pulled the drive out and looked and smelled inside, no smell of burnt rubber and as best can tell coupling looks OK. Upon a closer inspection of the prop, it has a rubber hub inside and there is what appears to an indication of possibly melted rubber. Going to head to the machine shop that has a press to separate the hub from the prop....looks like I may just have a spun hub on the prop....fingers crossed...!!!

 

[stonyloam]

You should just be able to drive the old rubber out pretty easily, and replace it. Oops, I Gus's some of then do need to be pressed out, mine does not, sorry.