"AlexE" wrote in message
...
Hi
I have a Tohatsu 40c (2 cyl) that now has a Tohatsu 10½ x 12 aluminum
prop. The motor turns about 6000-6100 at full throttle (max allowed 5800).
If i buy a stainless steel prop (I was thinking of a Michigan Wheel
Rapture), should I get a 12 or 13 pitch? Someone told me that in a case
like this, if the revs are slightly high, get a stainless prop with the
same pitch as the alu prop, that'll take some rpm off, presumably because
the alu prop flexes ever so slightly and the steel does not. The boat is
14 ft and weighs about 350+ kg including me. Comments? Suggestions?
Rgds
Alex

I can't picture an aluminum prop continuously flexing without breaking. A
good one for "Mithbusters". What are you using the boat for? Do you want to
zoom from one side of the lake to the other as fast as you can ... or pull
the kids around on a sled or a skier ... maybe tow a dingy? I would just
stick with the cheaper aluminum and increase the pitch. How much depends on
the above. Good luck