My tohatsu started doing that this year, I don't know why. I'll probably
have a mechanic look it over.
> Otherwise I really like my Nissan and am interested in hearing more
> discussion about going to a lower pitched prop. Does using a lower
> pitch make the engine more efficient at cruising speed -- i.e. does it
> run slower because the prop is more effectively coupled to the water?
My understanding is that a lower pitch will allow the engine to rev higher
and make its full power. On a lighter boat (say a rowboat) the stock prop
would be allowed to reach full RPM, but our heavy boats never get going that
fast so the engine is always lugging at a lower rpm.
> Or what is the advantage of the lower pitch. I'm an electronic type and
> can't quite get my arms around the concept.... If some of you
> mechanical types can explain it to me, maybe I can tell you about Ohms
> law or one of those other theoretical 'lectronic things.
Think of it as running in a lower gear.
FWIW, this is all speculation on my part - I haven't actually bought the new
prop yet, though I did hunt down a tach I'm going to try to adapt to the
motor to see just what RPM it is running at now.