Spun Prop on 115 suzuki115

[Panama Tom]

This might be a stupid question but I'm going to ask it anyway.
Our 18' Flats boat w/ 115 Suzuki has been running great until a couple of days ago. It runs fine up to 2k RPM when you go any faster it over revs. OK First thought is that I spun the hub. When I took off the prop everything looked fine I put it in gear and tried to move the prop, I was not able to spin the prop because I was turning the whole motor I could feel the resistance building on the compression stroke.

My question is can the prop hub be spun and have no outward signs and is there any way to test the prop? Every prop that I have seen you could tell because of the burnt rubber and chunks around it. Is there any way that this could be an engine problem and not the hub if so what should I look for?

Any help would be appreciated.

Thanks,

 

[steelespike]

You can remove the prop and draw a water proof line across the hub and body of the prop. do a test run and check the line.
If the boat is in the water all the time marine growth or corrosion might be causing ventilation.

 

[Frank Acampora]

Yes, a spun prop CAN function up to a certain RPM then slip. It will get worse over time and eventually will not tolerate any engine RPM at all. A prop that is not fully spun will be able to turn the engine against compression.

I think in this case you really do not need to test any further. Either buy a hub and insert it yourself, have the prop re-hubbed, or buy another prop

Oh, yeah! There is another option which will generate a bunch of contrary and vehement opinions: Pin the hub to the prop. I have done it on a number of props with good results.

 

[Panama Tom]

Thank you for your suggestions. I will mark the prop and test.

 

[skuhleman]

Thank you for your suggestions. I will mark the prop and test.

Thats how my prop was at first. Bought a boat and it had a spun hub. Would rev to about 2k before slipping. Just testing back to the ramp, by the time I got to the ramp it would only hold about 1200 rpms