Mark Hickey wrote:
"Yosimite Sam" wrote:


I have an acquaintance with a 582 powered kitfox that had this same
problem...It turned out that the prop was very slightly changing pitch....I
remember it took a lot of time before this was found out. There was wear in
the hub area. It was fixed by adding a shim. It seems like (I'm trying to
remember here) the prop hub was slightly distorted where it clamped
together.


It seems to me that the prop would be much more likely to go to a
flatter pitch and produce MORE RPM if the blade(s) slipped. Am I
missing something?

Mark Hickey

I guess it would depend on the rigidity of the blade and where it wants
to twist. A cambered airfoil should produce a pitching moment in such a
way as to reduce the angle of attack.

BTW: I did try the WarpDrive prop and the problem went away. I then put
the original prop back on to make sure that was indeed the cause, and
was unable to reproduce the problem anymore. So I don't know what's
going on at this point. :P