Prop sizes and sources
- Hello again,
I was just sorting the old messages to see if we had gotten a good
recommendation on prop size? Any recommendations?
Usually the diameter and pitch are stamped on the prop somewhere or
you can take it to a dealer who should be able to tell you what it
is. I recall someone saying that for a 40 hp engine the best prop
for maximum speed would be an 11 3/ x 10. I recall that mine has an
11 3/4 by 17 prop which came standard on that engine and I know I'm
not getting the recommended max rpm of 4500-5500 shown in the manual.
I bought a tach for a snowmobile which I thought would work to
measure rpm but if you have a GPS you can just measure top speed.
The most I've ever gotten with a light load and ideal weather was
about 16 and I've been told others have exceeded 20 mph. It's not
just important for max speed but probably gas economy and other
factors are involved. There are some places on the internet where you
can do some prop trading rather than buying a new one or you can keep
the old one as an emergency spare