Prop and RPM question

[retiredDon]

I have a 1998 Wellcraft Coastal with a 225 Johnson. My aluminum prop is 15 1/2 x 15. Bought the boat 3-4 years ago ran great. Maiden voyage the other day went to plane as normal was doing 30-31 mph at 4900 rpm's. After slowing down for a bridge the rpm's would only go to 4000 and the speed was 8 to 10 mph. Anyone have any ideas is it the hub on the prop? Is it something more maybe with the engine?

 

[Texasmark]

Not going to be the hub when rpms AND speed drop. Hub is inverse proportion, not direct!

 

[retiredDon]

Just a little FYI it was the hub on the prop. $85.00 later and the we were back to cruising.

 

[steelespike]

Typically when a hub fails it is total .Motor reaches a certain power and the hub lets go.No meaningful forward movement until the motor is slowed down.
Basically repeating the the same failure getting worse each time.