Test for a spun prop?

[water_rat03]

I posted on the mercruiser forum a few days ago and got some good advice, but still curious. Then I saw the prop forum.
So............ to avoid a long story, not my boat but wanting to know how to check to see if his prop has a spun hub. I know it can be marked and put in the water, is there any other way?
Long story short, a 1977 mercruiser 140 with the older style drive. He says the RPM's will run up to normal operating range for wide open throttle, but the boat will not "go fast". I have never seen the boat in the water, but did see it run. Prop spins when enguaged, goes into forward and reverse. The owner said when he is at wide open throttle the RPM's go up to normal but the baot won't get on plane. The drive runs quiet, no grinding or unusual noise.
Any way to test the prop without putting it in the water? The lake is 50 miles from where he keeps the boat.

 

[steelespike]

Re: Test for a spun prop?

A spun hub is just plain spun.Boat will accellerate to a certain point, the the motor will rev off the dial if you let it and the boat will slow.If not to badly spun you can slow and it will grab and then let go again with the same results.What size prop? on the barrel or under the prop nut.
what is the actual rpm it reaches.If he's guessing don't believe it. Could be a greatly undersized prop(not
likely)More likely missing a cylinder,throttle not opening all the way, bottom badly fouled,prop badly damaged.