"Injam" wrote in message
ink.net...

It would seem to me that in order to go faster the propeller would have to
spin faster.


Or the same speed with a higher pitched prop. In your example, 6000 RPM is
about max for most outboards I know of. If the engine has enough extra
power to swing a higher pitched prop at 6000 RPM, it will be faster, for
sure.

RCE